On the floppy swap if u put in a HD 1.44 it will still only be able to do 800k the only way I know how to get around this is on the SE you need to get a rom from a SE FHDA. I looked into that almost 11 years ago when that was my personal machine my dad let me do whatever on until I got a 6100 and then it ran appleshare on it for a while. I still have it along with system 7 install disks all on 800k floppies like about 10 of them. I can probably boot it up and make a disk image if that would help though it has a supper big for it 320mb drive in it.
MDD Dual 1.42 Ghz, Flashed FireGL X3 to X800, Sonnet Tempo SATA with Raid 0, M-Audio 7.1
MDD dual 1.42 Ghz still stock