5 things Call of Duty should have sorted by World at War but didn't

 Once again I have felt the need to play through a Call of Duty game on its hardest setting, Veteran, and, as usual, various sections of the game have proven to be so excruciatingly difficult that they have angered and frustrated me into thinking about the game's most significant gameplay problems, some more obvious than others, and also into feeling the need to tell you all about them.
 This time the game is World at War. I've recently bought it on PS3 but have completed it before on Veteran  on the 360.
Apparently a lot of COD fans aren't at all keen on WaW, apart from Nazi Zombies obviously, judging by internet chatter but they're wrong and can fuck off because I like it.
 Anywayz here are the five things, some of which were sorted in Modern Warfare 2, with brief descriptions:

1) Grenades - Ridiculous. The cause of the majority of my deaths on Veteran. Combined with number 2 turns any open ground into an endlessly replenishing minefield.

2) Infinitely spawning enemies - A problem that Infinity Ward explicitly addressed for MW2. Combined with numbers 3 and 4 and some bottlenecking level design makes advancing in some cases virtually impossible and only possible with a lot of luck on your side.

3) It's always down to you to push forward - Another common one for the COD games and closely tied to number 4. Without this problem most of the others would be a lot less significant and frustrating as pushing forward is a key element in a lot of the series' big battles.
Leaving pushing forward completely to your AI allies is a cop out so perhaps they could push on slowly and your input is to speed the process up if you can...

4) AI - As lovable as they are your AI team is shit when it comes to killing baddies. Of course they have to leave the fun to you but they really do seem to be there just for show.
 This is made a lot more obvious when the enemy AI enter the equation. They shoot you, and only you. Surrounded by other targets they will take you out through a 5p hole in the rubble from a mile away.
 Now World at War gets bonus points for its super-retarded enemy AI that seemingly came out of nowhere, although, amidst the frustration, it can be quite funny imagining the thoughts of the Nazi soldier who decides enough is enough and a jog over to the Russian and back would do him the world at war of good.

5) Checkpoints - Perhaps the least obvious 'thing' that becomes very obvious on a Veteran playthrough is the   frequently flawed placement of checkpoints. The game is made up of action sequences broken up with brief rest periods, often used for dialogue or plot progression.
 What becomes apparent is that the checkpoints are almost always placed at the end of an action sequence and at the start of a rest period. So what could start off as a simple walk up a hill or ten second chat turns into a complete pace breaker on your fortieth respawn. The checkpoint should be at the start of an action sequence.
 Of course they're not all like this but pfffff.

Anyway fuck it nobody cares, hopefully Black Ops will be good BYE

Update: It's just occurred to me that I think the problem I have with the Veteran playthrough of WaW is that it's hard to roleplay as a Russian soldier when your comrades are running headlong into the enemy and you're cowering behind a sandbag every five seconds waiting for your health to regenerate...