Just about every question is answered here.
http://forum.ppcgeeks.com/showthread.php?t=51532
In short,
1. wktask,
http://soft.photoracer.net/docs/wktask_en.html
2. Samsung Keyboard is the largest. There are some better alternatives though. Check out SPB keyboard, Resco Pro keyboard, FingerKeyboard 2, and Cootek Touchpal.
Not all will work in Landscape.
3. .net 3.5 should be in that thread, but if not,
http://cid-ab9de24be9af1b9f.skydrive....wm.armv4i.cab
4. Check the thread linked at the top.
5. Are you using the widgets? Dont think there is a fix for that, but I will look into it if nobody else has suggestions.