Yea, but this is only for very good computers... It depends on many aspect... How many cars are in video? is it video from MP or SP (SP si much more demanding), etc.
Ad. Quality... you have to experiment with this aspect, take some 10s video example and try to change options of rendering.
Nope, System Shock 2... I have never played Serious Sam ... System Shock 2 has got very good atmosphere. And at all time, you have got feeling, that you are fight for your life.
If you aren't team leader in 3D, team leader can delete you from team, if you are team leader, I think, you do that yourself. Just go to Drivers/team database and search your team. Then click on edit button and you'll find it somewhere there.
Doom 3 is very different from Stalker. I think, that most possible alternative is TES: Oblivion... Yeah, I think it is mix of Oblivion, F.E.A.R. and it have something from SS2 for me