OK, I think this is what I've learned from this thread:
The floppy drive's belt is broken. It's too difficult to get a replacement, and if I had one, it would be too difficult to put it into the drive. (Because one of the drive's screws, as it turns out, is stripped, I tried to open the drive caveman style. Not only have I probably eliminated any remaining resale value the drive may have had, but I found within the drive is some kind of shield covering the drive mechanism, and I didn't see any way to remove it either.)
Also getting a replacement drive is too difficult, and if I could find one it probably wouldn't last very long anyway, because ALL possible replacements have belts that break easily.
On the subject of suitable replacements, it turns out the drive's connector, right down to the damn internal one, are Toshiba proprietary, meaning only other drives from Toshiba laptops can possibly work. As noted above, the damn things are all ticking time bombs. (And this is in contrast to the CD drive, which is standard slim IDE!!)
It doesn't seem like the connector has any documentation available, or been reverse engineered or anything either, meaning no converter to a normal floppy drive could exist.
As such, I think I might just have to consider it a complete waste of my time to try and give this damn laptop the gift of being able to read a floppy or floppy-like disk. I still want to use the computer though, partly because it's a portable computer that can natively run DOS and Windows 95 and isn't broken, and also it has a Yamaha OPL3 chip damn it!
So, what to do about this computer?
Well, in the course of this thread, I have learned the hard drive is very easy to remove, and is standard 44-pin IDE. (Used in just about every laptop drive before SATA took over, afaik)
As suggested by Deksor above, something much easier to do would to be install the hard drive in a PC with more favourable boot options, and put format it and stuff from there. (Maybe I don't have to do a whole OS installation? That would simplify things because then I wouldn't have to worry about wrong drivers... like, maybe I could just copy DOS and a CD driver and that program (I forget what it was called) that lets you boot CDs.
And maybe I could replace the HDD with a CF card, it's bound to break one of these days...
Further on the subject of this computer, I have decided to remove the main and restore batteries for the time being. I should probably get rid of at least the restore battery, as it's pretty useless to me, not sure about the main battery. It didn't look to be in the greatest condition, but maybe it's just cosmetic. It did seem to work. I wasn't sure about the CMOS battery, I left it in for now, but it didn't look so great. And I'm not sure if these super old and kind of strange (by modern standards) batteries have any particular handling precautions when being disposed of.