For someone that's only prototyping and only making small amounts of circuits, does it make sense to build up a stock of "normal" diodes at all? Or should he go with Schottky diodes, like the 1N5819?
What are the "exclusive" use cases for normal diodes?
From what I've seen so far they have be (ab)used to bring 5V signal levels down to 3,3V (utilizing the forward voltage drop). What else is there?
There was a good discussion of the differences on this board recently. You could search for it. At the extremely low cost of diodes, I think it would be dumb to not have both kinds if you are dubious about the uses.
If your question is really, "can I always use a Schottky in place of a normal diode?", the answer is no.