yes you can. There's no difference in the games except you have to need to be at the firmware that the game requires which comes on the games anyway.
There are no such things as version specific 'PSP1000 games', there are only PSP games, and the UMDs can be played exactly the same on PSP 1000, 2000, 3000 and E1000, but not the GO which lacks a UMD drive.
Yes, the NDS lite can play all DS games
No. But, you will be able to play ds lite games ont the 3DS.
Yes you can play Nintendo DS games on a Nintendo ds lite.
Yes, you can play DS lite games on the DSi as well as the DSi XL
It can play GameBoy games and DS games.
No. There is no way to download or play DSiWare games on Nintendo DS or DS Lite systems.
Yes, DS games are region free.
Yes, they can play the dsi games.
Yes, the original Nintendo DS as well as the Nintendo DS lite can play NDSi games.
yes but 3ds games don't work on a ds lite
Of course not.