Is it possible for a player to get inducted in the HOF without every making a pro bowl? Colston's numbers are getting close to WRs already inducted and he will likely surpass them on sheer numbers.

I don't see why not. Ever since they started allowing fans to vote on the ProBowl selection, it's become more of a popularity contest than a true indicator of who is best in the league. Might help if he could get a few All-Pro selections though.