I agree the youths the first few aren't worth! So upgrading (and skipping those) is easier. People who skew their Quality for Cup might find them of use, but I didn't.

All facilities that produce anything will have the timer reset when you upgrade, keep that in mind, you don't want to miss boosters. Never speed up building, but build as often as you can. Yeah I did notice injuries go down, especially at the last turf upgrade. I power trained a lot at that time so the savings of reds was easy to see.