Hello and welcome to Clubsnap! Please enjoy your stay here and post often!
The 400D is a very good beginner camera with a fair balance between features, price and build. Disadvantages would of course be the small size (perfect for shooters with small hands eg kids, sec sch students). If you have a big hand, there is the extra BG-E3 battery grip for more ergonomic comfort, and the ability to slot in another battery.
The 400D will not become obsolete so fast. Up till now, there are people using the 300D, and there are 'new' 350D DSLRs in some shops (like harvey norman @ Plaza Sing). The 450D will be coming out soon, so lets say you get on the canon pathway; you'll have a few options to take:
1) Get the new 450D when it arrives later in the year (May? June?)
2) Get the 400D after the 450D is released. This will let you have a new 400D at bargain prices.
3) Get the 400D now.
4) Get the 350D now.
What do you mean by kit 1 and 2 though? You mean like, the 400D body with 18-55 (kit1) and 17-85(kit 2) lenses? That isn't a very good consumer option. I'd rather you get the 400D kit 1 or 2, and get yourself a value-for-money 50mm f/1.8II prime lens for S$110 (new). It's a lens that a lot of us own and highly recommended by everyone. It's a non-zoom lens (prime), meaning that you'll have to move to get the shot you want. Advantages would be a wide aperture (meaning that it's easier to capture fast action shots) and good sharpness.
IMO, sweaty palms wouldn't degrade the quality of your camera. Unless of course, you sweat acid, then that's another problem >.>
Hope this helps =) If you have any queries about the 400D, please check out the Canon sub-forum or contact me through PM or MSN!