Well when permission is taken away.. That's still stealing. Even with the Titan. Riker was only 44 years old when he took command. Still relatively young
When we see Riker for the first time (Farpoint) Frakes is in his mid-thirties, Nemesis is fifteen years later. So early fifties,
Frakes could've been portraying a character who was younger than him or older; it's impossible to claim the character was the exact same age as the actor if there wasn't an establishment given. At this frame in time his age is pointless, some people appear better than their actual age and some look worse. It all depends on eyes of the beholder, so early 50's for you and to others another age entirely.
Riker's birth date is canon, so I don't know why you wouldn't use it. He's 29 in the first season on TNG. Picard isn't the same age as Patrick Stewart either.
Riker's age comes from the TNG S2 ep "Icarus Factor", where the writers describe an event that affected Riker at age 15, but also have a character refer to that as having been 15 years ago. Room for rounding errors with the latter, but not much - it would make no sense to think it's actually more than 20, say. ...And never mind the writers probably got confused with their fifteens there and may have intended something else - the character couldn't have been wrong in this special instance, merely inaccurate by three-four of years at most. (It's Will Riker himself speaking, after all.) The only time we return to Riker's age is the Okudagram in "Conundrum", not originally readable but still subject to freeze-frame analysis now. Timo Saloniemi
The writers mysteriously made Riker 5y younger than Jonathan Frakes. I guess being offered his own command at age 34 after a mere 12y in Starfleet wasn't "impressive" enough. Yes, taking command of the Titan at 44 was Ok, but consider that if Riker had taken command at a time that made sense (i.e. Icarus Factor), he'd have been a captain at 31, with his career boosted by a tour on the flagship. He commands bigger and bigger ships for 12-14y, and he's a RADM by 45. That's the career path that made sense. Unfortunately, both Riker and Data had their career advancement smashed by the insurmountable problem of the audience liking Patrick Stewart, Jonathan Frakes, and Brent Spiner too much to get rid of any of them.
Considering average age of a Major (US Army) is 33 and Lieutenant Commanders (who often "captain" third-tier vessels in the RW) are promoted after 10 years in service on average with a minimum of 6.5 (so 28 to 33 years old), I would agree that being offered a "captaincy" at 34 is only "impressive" if it also comes with the rank of Captain (O-6) rather than merely the title, as it's not impossible to make it to that rank at that age in the USN but its right on the legal minimum for most. Never stated. However, the previous known benchmark for "youngest captain" would appear to be James T Kirk who was promoted to the rank of Captain no later than 31 (when he took command of NCC-1701), but potentially counting back as much as three years before based on other material, or Picard himself who may have been as young as 28 when he took command of Stargazer, based on a birth year of 2305, a 22-year captaincy of Stargazer ending in 2355. Therefore, she was certainly not intended to be more than thirty, but could be assumed to be as young as twenty-seven based on later evidence.
Riker was offered command of the Drake at age 29. He decided that a tour on the flagship would be better for his career, so Paul Rice got the job. And assuming the holographic replication of him was accurate, he was a four-pip 0-6 captain. So presumably, Riker was offered that rank. Given that Picard recruited him as a LCDR, Riker could have skipped CDR rank completely.
Or he would've been a full Commander with a captain's title. No way to know what happened in Paul Rice's career that he ascended to the rank as quickly as he did.
Interesting question. I have to say I honestly never thought of Riker being promoted to Captain prior to First Contact. I figured he would be promoted when he accepted his own command. I just figured he'd stay Commander otherwise. The Enterprise-A was a bit of an unusual situation. Spock was already a Captain by the time TWOK happened. It just so happened that Kirk was demoted to Captain and given command of the Enterprise-A. Spock certainly could have commanded another ship but he chose to stay with Captain Kirk as his first officer/science officer, and likely due to his stature, along with Kirks, that was granted. I got the feeling that was not a usual situation on Starfleet ships, to have two Captains of command rank serving on the same ship. And it just would have felt wrong for Starfleet to demote Spock to Commander in that situation. Kirk did that to Captain Decker in TMP and he probably took that as a black mark on his record. Scott was Captain of engineering, which isn't really the same as a command officer, so I don't necessarily count that. In TFF and even at one point in TUC, Commander Chekov has the bridge when Scotty was also on the bridge, even though technically Scott outranks him. I think because Chekov was a command officer (and a former first officer as well). Scott was not, though he certainly could take command if the need arose.
Yeah, the Enterprise-A was unique. It was a PR exercise, basically Starfleet throwing all their rotten eggs in one basket where they could keep an eye on them. Sulu got time off for good behaviour. The only two missions we see reflect this. They are sent to Paradise City specifically because Admiral Bob thinks Kirk will cause the Klingons to "think twice". In reality it does the exact opposite. He's sent to escort Gorkon because his hatred of Klingons is well-known and will make him the perfect fall-guy in the conspiracy. It's clear that Cartwright pushed behind the scenes, and perhaps influenced Spock to 'volunteer' the ship.