The tank is not so hard as you might think. Shotgun is his worst enemy. So there are two tactics. Shoot him down until he is death it is as simple as it sounds, just make sure you are running. Or burn the tank and run all the way back, not forward as I believe they will spawn when you go forward and not backward. What you never should do, burn the tank and shoot him. The tank moves faster when on fire you can't outrun him then. Have a good molotov thrower and start to retreat as soon as you see he is on fire. Both tactics work. You can even solo the tank as soon as you learn his tricks.
Nice link but most is so wrong. I did expert on full speed ahead and with checking every room for supplies. If you keep running not too fast of course normal infected can't outrun you which means you can't get hit. There are some spots you can better run if it is very open for example. Run in, shoot a bit and return to the other three and kill those lured infected with it. Assault rifle is good but shotgun is better, there is hardly any range and you just get close. There is no danger to that as you just need one shot anyway, although that might be getting used to. I recall I did Dead Air with someone who used the sniper and we were the only two left he started to picking them down from range I shotgunned the ones getting close. So it can be good but remember if one has the sniper you lose a lot of damage vs the tank if you don't have a molotov.
Safe tactics are good to of course but practice your running as there is no sense in crouching there and getting hit, besides you need your running skills vs tank anyway if you got no molotov. I never took longer than 90-120 minutes to complete one campaign with bots or good people.
Maybe I must play with you all one day. I don't use headset though as it is no rocket science what you should do. One last thing remaining. I indeed also use the captioning and recommend you do, seeing hunter growls on your screen can give you the edge, same applies for vs.