Thank you for posting this. This is what I hate about prospect evaluations - folks dramatically oversimplify it, as if a prospect is inherently either "good" or "bad" and it's just a matter of figuring out which one it is, like some kind of chemical screen test - give the prospect a drink of X and if they turn purple, they're "bad."
Life doesn't work that way.
There are so many factors that go into whether any prospect, and a QB in particular, will turn out to be a good pro. The quality of the structure and strategy of the organization that drafts them, for example. Their own work ethic. The skillset of the players around them. Luck, injuries, etc.
What I take from the OP is that there are good reasons to think that Allen will buck the trend of sub-60% college QBs, in other words, he's not as high of a risk as some have made him out to be.
Fine, point well taken.
But to go any farther than that and state with near-certainty that Allen is going to be "good" is simply a waste of time - it's unknowable with Allen, or any other prospect.