I don't read level feelings. Ever. Sometimes I realize it and try to find it in the message list just after it's too late =)
I don't use running as much as I could. Even when I need to run for a healing globe, I tend to save running for... no idea what.
I forget to use the rocket launcher (even though I always carry one with 10-20 ammo) to make things easier for myself. I often even run through lava rather than blow a hole in a wall a go through there instead.
I succumb to these a lot, but I usually blow up walls before walking through lava unless it's just like 1 tile.
Allways going for 100% kills cause its cool.
Damn right it's cool. More like awesome habit.
Reloading the chaingun after every former kill (and getting shot by his friend that came out of the dark)
I usually pop behind cover before reloading, but I still do this sometimes.
For me, it would just be not dodging. I know I can, but I just stand there and take hits...so stupid...
I used to suffer from this. It's not that big of an issue now that I avoid firefights and hide around corners and fight in melee. I do make sure I zigzag a bit when I'm retreating or charging in, but on the rare occasion that I'm in a real shootout it just doesn't seem worth the trouble since they'll often just shoot at me again after I dodge the first time. Plus it can be kind of frustrating when the speeds are slightly different and I don't know whether it's safe to shoot - so I just shoot anyways.
Also not moving to pump the Combat Shotty, but just using R.
Well, this depends a lot on the situation. For corner shooting, mashing R is the only good choice, and if you're fairly sure you can kill something in one more hit, it might be better to just manually pump and shoot in a very short time rather than risk getting shot at even with a dodge move. My big issue with this lately, is that I upgrade to the tactical shotgun and forget that I don't have to pump anymore, so I waste time reloading between shots.