I think you need to upgrade the tasollar to 2.0, to follow that guide. (It is purely software based, it's just people all call it firmware upgrade...) Tasollar is no longer a keyboard after upgrading and the FN1, FN2 will work. My keyboard also doesn't work as the dll files chusanApp and inject.exe are using assume that we are using upgraded tasoller, not keyboard. (bin folder from the "team" he mentioned.) I don't know if there's a version that takes in keyboard inputs like what new+ did. Nor have I tested on the original chusanApp directly from source files to see if they work for 1.1 Tasoller, sorry. Regarding songs, my A000 is 7.49GB after pasting all ASUN, ASAN, AS01, AS02 into the A000 folder. You must merge the folders, (cueFile with cueFile, music with music, etc.), not just leaving them as ASUN, ASAN. There are lots of duplicated files and I kept the original A000 version of all of them (they should be identical anyways). I also pasted A114, A201, A202 from new+ into the option folder, and A041 into the option folder (link a few pages ago, should be 4/1's songs + arc songs). This gives back the Ultima songs and the world's end songs (maybe some options are not needed, but I don't want to test them as they are already available...). Your best bet maybe to first figure out the songs using the partially available keyboard input, then try to figure out the Tasoller upgrade. So if you are out of luck with songs, you still have new+ directly available. Hope this helps! (Please point me out if something is not correct, but this is what I did.)
Regarding sound, I don't remember repatching it using the modder but directly used the chusanApp from the new bin folder. Maybe try to plug your speaker into the headphone jack at the front of your computer, instead of at the back panel? (I did this for new+ and sun, both worked fine. Don't know things beyond this...)