I have some pointers for everyone to use, new or experienced to the game. I will go over your points to critic them. Please don't think I'm defending hackers or attacking your viewpoints. These are common mistakes I see all too often and I'm just trying to help.
Most of the time players that are thought to hack are just good players. There are still hackers that ruin the game for everyone and can using be reported in-game or on that clan's website. This game has been out for over two years now. With a game being out this long you really have two types of players, ones that have been playing the whole time, even with additional new accounts, and those that are new or not as experienced. I myself have over 2600 hours in the game and can often go 4-10 KD during a match and also often get called out for hacks. Many of the experienced players still left are in competitive teams, as some of us are, and purposely join servers with less experienced players.
Many skilled players can get 30+ kills with only a few deaths, even from a low rank account as many also have multiple accounts due to reaching max rank, going for high stats on just a few weapons, or being banned from servers just for being too good. Please don't be the guy that gets angry over every time you die, learn from that mistake. Think about why you just lost the engagement to that player, really think about it. Did you come around a corner unprepared? Were you not paying attention to your surrounds and let them sneak up on you? Was your reaction time not fast enough? The best way to combat these players when all else fails is to use teamwork and call out every movement you see.
A lot can happen in the time you are not looking behind you or not paying attention to your surroundings, even if only a few seconds. Most of the time this happens to you it's because you are in the same place for too long. Never stop moving! I hear all the time "how did you know where I was?". When someone is holding a position, even for just short period of time, you can create a lot of commotion, by shooting and being heard and showing on the minimap, or just in a spot experienced players know to check first. If you can afford it, the best equipment you can buy for this game is a true 5.1 - 7.1 surround headset. I have one and can pinpoint most people in my area and stop players trying to come from behind without looking at the minimap. It was the best investment I have made for this game besides a great mouse, keyboard, and monitor.
Learn recoil control. Besides knowing the map and where players are likely going to be, the next thing you need to nail down is recoil control. This is what sets skilled players apart from the rest and how you win engagements. I can move and dodge enemy fire and still take down a few enemies while being engaged. Spend countless hours in the Test Range! If you cannot negate the recoil from the weapon of your choice, then keep trying. Pretty much all weapons in the game can be controlled with very little recoil once you are experienced with it. Again, I can't stress this importance and like I just stated if you can't control the recoil KEEP AT IT! Some tricks you help you in this is to play with mouse and sensitivity settings and burst firing until you get it right. One more time, all weapons can be controlled with enough practice. You say "I can never control as much as the guy that killed me, he's hacking!", well you haven't been practicing enough.
There are a lot of great snipers in the game that just know the correct bullet drop for any distance. One thing that will help you tremendously with sniping, is to not get into long engagements and to keep them close. If you must get into long engagements, learn the rifle you are using first. It might take you a few shots to get down the bullet drop or dial in the range with the V key from a certain sniper rifle. Look for landmarks. I like to look at the closest objective since the range to it is displayed and calculate from there. Use the 8x scope. The mil dots are usually at every 100 meters for most rifles, but can be a little different. You can guess that someone is 350 meters away by being ~50 meters past the objective. Dial in your range with the V key and place your sights on the enemy between the cross hairs and the next dot, head shot every time!
The best way to take down an enemy mortar that is decimating your team is to use a MAV from the recon kit. It will lock on once in sight.
I'm really just trying to help you and anyone ready this. I have told many of our members about these points, and the ones I will go over below, and have watched them become better players. Here are some additional points I would like to go over:
Reaction time. Not all of us have the best reaction time which will cost us during engagements. Work on real-life hand-eye coordination and reaction drills. One I could think of would be to have someone throw an object at you, which they will try to trick you into which angle it will come from, and you will have to catch or deflect it. Many pro players do this before matches. I know this sounds stupid, but it can up your reaction time and hand-eye coordination. If this can't be done use the Test Range. Pick your weapon of choice. Stand behind one of the concrete walls, peak around, and try to get your sights on one of the targets as fast as possible, don't shoot yet. Keep doing this over and over, until muscle memory will place you on target where you want every time. Next do the same drill but this time fire on the targets at different ranges and positions and think of it as each enemy as you are coming around a corner.
Recoil control and precision. Skilled players can place more shots on target faster. Spend some time with the weapon of your choice, usually a high RPM weapon, and practice getting as many rounds from a magazine on target as fast as possible in the Test Range. There is another drill I like to do similar to the one for reaction time, modify it a bit for recoil control. Peak around a wall and take out as many targets as quickly as possible with the least rounds. Again, keep doing this over and over until you can take down all the 4-6 close targets with one magazine as quickly as possible. In order for you to do this, you will have to master the recoil for that weapon. The next drill would be to find a wall that does not get damaged from regular rounds, aim at one point, and fire the whole magazine while trying to keep your sights in the same place without moving. Check the bullet wholes on that wall and keep doing this until your groupings are as small, width and height, as possible. Repeat this drill but with manual burst firing until your groupings are even smaller, all while as fast as possible.
Know your surroundings. Keep playing all the maps that you have access to. If you have a map you are particularly bad at, keep playing it! Try to imagine any spot an enemy could be. Check every corner, every object that can be used for cover, every spot you have camped before, all while moving as quickly as possible. It's likely someone could be there and prepare accordingly. You will start seeing patterns on where and under what circumstances someone will be in a certain spot. Never camp a certain spot for too long. The reason most players go on crazy streaks is because they know how to move and manipulate the battlefield.
Control and out-wit your enemies. I can give you a few pointers, but most of this will just come from learning yours and others play styles. Most enemies will hide under cover when engaged from medium to long distances, use this to your advantage! If you see an enemy or even a few that have spotted you first, lay down suppression fire to get them to cover and pin them down then flank the from another angle to clean them up. This may require an executed attack from a friend or teammate. Instead of assaulting a doorway or choke point directly, lay down some fire or a few grenades to get to think your are coming straight on then flank and come from another angle of attack. You can also make them think you are a bigger presence and are several enemies and get them to move exactly where you want them by using a bunch of noise, example grenades. Try to push enemies into other teammates instead of taking them all on your own. Teamwork is key. If teamwork is lacking, then everyone will suffer!
PTFO, play the fucking objective!
As coming from an experienced player, I am just trying to help with what I know that makes me win fights. I have learned that running and hiding to avoid getting killed and trying to get a better KD is not the way to go. Learn how to win engagements! If anyone reading wants me to critic their gameplay, record some matches and message me a link. I will either make a reaction video or message about what you could do better. Let me know if you have any other questions!