There are lots of dimensions of 'talent', some of which matter more and some of which matter less to being a successful QB.
JM is FAST, he appears and is said to be super strong, he can throw the ball a long way and/or throw the ball hard. Of those strengths, only 1 really matters for being a good QB.
What JM hasn't yet shown is:
The ability to know plays/D formations and make pre-snap reads
The ability to make reads, even simple reads, during a play
The ability to get the ball out quick (this isn't about the throwing motion, it's about his processing before he even starts to wind up)
Ability to be consistently accurate with any depth/length of passing.
All these are REQUIRED for being an average, much less being a good QB and really, if these things aren't there, it doesn't matter how hard a person can throw a ball.
ABSOLUTELY!!!!