Hello, I will attempt to address these issues before pasik comes in and gives more solid explanations.
1. Weapon selection is random when you join the game, but after you join and die, you will always spawn with the same weapon you had in your hands at the time of death. So actually, you can easily "select" your weapon to have with you the rest of the game. I think there may be something implemented about selecting spawn weapons but that will come much later. Also, did you know you can knife crates to get weapons and stuff? (not being an ass but lots of new players don't know that)
2. The G36 and AK47 are very similar but the AK47 is a little more inaccurate and the G36 looses its kill power earlier on. The weapons are G36, AK47, M24-A2, MP5sd, M240, and Mossberg. The MP5 is silenced to AI so AI react extremely slow towards shooting it at night especially. The M24 is a sniper... the M240 is a light machine gun, and the Mossberg is a shotgun. I'm not quite sure how you can't tell the differences. More weapons will be added as niches for specialties are discovered and added.
3. Not much to say here except that AI is always an area of improvement.
4. Agreed. Sometimes, standing next to a grenade box is more effective than artillery

5. Hmm troop transports are being tested upon and implemented already. We have the idea of having jeeps, apcs, and tanks for player/AI driven vehicles. The jeep will be a light carrier and recon vehicle (like in company of heroes), the apc will be the main troop transport, and the tank will be the tank...
Also, RWR is not a WW2 game... as shown by the choice of weapons. It is a modern warfare game. If you are looking for a WW2 mod, I highly suggest Petrenko's WW2 mod in the mod section. It does a good job of adding weapons like the garand and trenchgun.
6. Good idea that has been thrown about on the IRC.
Anyway, I hope you enjoy this game and its community
Good luck,
ComJak