I tend to agree with your overall thinking - my only thing is, we have to account for the refs too....
They already got too much to deal with and eventually it would get "clunky" with multiple injuries on back to back plays , multiple players - the TV networks would have to come up with some sort of visual representation (play countdown to return type thing) of how many plays this guy have to sit out, and how many plays this has to sit out, etc.... I see it getting clunky quick and errors made: Ie, player returning after only sitting 4 plays.
How about a compromise? Can't return until change of possession, FG, or TD is made .....*OR* a 5 min max countdown?
This way a kid could literally return the very next play in quite a few cases. But on long drives the max would be 5 min. That would still introduce some un-needed confusion imho, but it is a compromise.