It should work.
no
Yes, Lego Star Wars for the DS will work on the DSi
LEGO Battles can't be played on the Nintendo Wii. It can be played on the Nintendo DS, DS Lite, DSi, DSi XL, 3DS (without 3D), 3DS XL (without 3D), 2DS, New 3DS (without 3D), and New 3DS XL (without 3D)
no you can't play dsi games in ds but you can play ds games in dsi.
LEGO.
Yes. The game and the DS, however, are $$$.
yes you can any ds game works on any ds console unless it is a game chip(r4 etc)
YES, THE DS AND THE DSI can play toegether.
You can get the DS game from anywhere DS games are sold.
No, the R4 for the DS will not work on the DSi
No but DSi can play DS games.
Yes, the DSi can play DS games