- spaces and numbers are not important
- wa and wo and n wouldn't be used in the naming screen since the sounds can be replicated by "u+a" "u+o" and "nu",
and we put the " dakuten in the last extra space.
- p-series sounds like b-series anyways so the ° dakuten isn't much of a loss, and Dragon Quest players already avoided dakuten altogether since they take extra space.
1. I don't know about StarTropics 2 hacking specificly, but often space tile is also used as the background and numbers are probably important the HUD. I just checked and the numbers are indeed used for chapter numbers (if you press Select to pause it shows you the chapter number)
2. I don't mean it to be a rude but did you study much Japanese? I admit my Japanese skill is shamefully poor, I don't know enough to comment on substituting わ as "うあ", but を is NOT the same as "uo", as I've heard it is used as a subject market in sentences exclusively (and pronounced "o"), and ん is most definitely a different sound than ぬ.
Maybe you could get away with removing the window border tiles.
"Idiotic question" does not seem to be used in a rude context here, it could be used if he is apologizing if his question sounds bad, which sounds like the meaning here.