1. I don't see Peyton as a full time TV announcer, maybe guest every now and then, but definitely not full time. You are talking about going from making 8 million a year as a player to less than $250,000. I'd say he'd say "thanks but no thanks". Marino and Montana are from a different time period. (No they aren't that much older) In their prime the pay scale was a fraction of what it is now, they are working because they still need money.
2. I can see Peyton coaching somewhere. I'm not sure if he'd want to listen to the bellyaching here, but I can see him coaching. The money although less than a player, in the SEC is getting pretty close.
That said, I'm not sure how his personality would work out as a head coach in College. Peyton is a perfectionist, and that's well and good except he expects everyone around him to be a perfectionist as well. I'm not knocking the guy just saying that at times it seems to me he rubs the other players the wrong way and sometimes they accidentally slack up let him find out he can't do it all alone. I saw it happen at UT a time of two when he was here and it cost us chances to play for championships SEC and National (Memphis 1996)
It's a chance you take as head coach. It depends on his willingness to take the chance of failure overriding his past success. Do you take a 4. something million dollar contract to come to UT and coach football with the chance that you might fail and be ran out of town after being the top QB in school history, a superbowl champion, etc. Or do you take the safe way out and spend the rest of your years making a pittance here and there doing tv, occasional sponsorships, and managing the millions you socked away during your career as a pro quarterback.