Even if there is a fool tool like SRPG Studio, you will also need to read its docs and examples instead of just saying " Who can tell me how to use it?".
Can’t speak on changing theme but from what I’ve seen, music hacking isn’t so much hard, just tedious. though that can be said for much of hacking, but it doesn’t seem as bogged down in technical no-how as ASM does.
Background editing though? Easy as piss. Fuck, even changing the opening crawl graphics in FE7 are easy which is why it’s depressing seeing no one change them.
Music hacking is not even tedious. Insert instrument map of your choice, convert MIDI using MID2AGB, insert using Sappy. It’s just that the Ultimate Tutorial teaches an unnecessarily complicated old method.
Maybe the background part seems easy to me 'cause I worked on my hacks back before FE_Editor was a thing and we had to cut up and grey-scale our mugs just to insert them the same way you would a background, map sprites and other things like that…
I’d get to 8 fairly easily. Then I’d have to work and learn new stuff with 9-11. Then I’d again have a super easy time with 12-13. Lol I’m weird and nonlinear.