HOF? Absolutely. Fast track him.
Retire #1? I think there is a better option....
Here is an idea. We could place a higher standard on issuing the #1 jersey to a player. Don't just let players claim it. Only award the jersey to the top WR on our roster, when the consensus of the coaches agree the WR has achieved the same level of work ethic, leadership, and success that Darden exhibited. This means the #1 jersey may not be issued every season, but when it is, it will go to a very special "team captain". It could be a good recruiting tool too.
At some point, if the list of WR's that wear #1 were to grow even more distinguished, than maybe a space on the wall at field level can feature the #1 and list the names of those that were awarded the jersey. Just a thought.