Bob, I enjoyed following your train of thought! It all sounded very sensible. But moving fingers quickly actually doesn't take long to achieve. Bernhard has a brilliant outline of this somewhere. Forgive me if you already do this-- it's so hard to know each other just by writing, isn't it-- and his explanation is better, but here's what I do:
1. determine all the various positions; for example, the RH C scale has two positions, C-E and F-C...
2. practice getting to those localities on time (this is fun with accompaniment), noticing the shifts needed to get into place... and
3. play the notes within those positions as fast as possible. I mean, you could break it down more if any of those segments feels uncomfortable, but that's my basic m.o. If you can find Bernhard's treatment of this situation, it's fantastic.
As far as the 3-4 trilling thing, it's pretty unusual to HAVE to use those fingers to trill. Some late Beethoven, some Scarlatti (?) dep. on interpretation, but I play a lot of trill-ful repertoire and have rarely needed to use those fingers.
About reading fast enough, I don't know what to say about that. I think strong reading is important for classical performers, but I sense that I'm in the minority in this opinion. I know that most people do learn music that is more difficult than what they can really read, so I guess it can be done. I'm afraid that's not a very helpful observation! Hope the rest is, though.