Playing devil's advocate here but almost all those ideas are not doable:
1) That would only break the game because of the inevitable influx of players languishing in the GLA's Guild that it would attract, which is exactly the reason had PvP in the Wolves' Den in a dedicated instanced area well away from any city - to ensure the servers are stable. Ul'dah's main street on Balmung at least is already a laggy mess, this would just make it worse.
2) No, players just have to stop being so lazy they can't take five to ten seconds to run and zone into the next area for the Market Board (really, I have no idea why SE moved the Limsa aetheryte from it's original 1.0 location in a side room near the Aftcastle in the Upper Decks down to the Lower Decks near the Market Board, but had the ones for the other two cities well away from it).
3) Mhi Khetto's Ampitheater is specifically designed for seasonal and special events, so that would only create more clutter when those events are running.
4) Law of the conservation of detail. Buildings that are accessable will generally only be those needed for gameplay or the plot (this cuts down on development time, while also reducing the amount of server processing required), so I do not see this happening. (Also SE seem to be against the old RPG trope of being able to break into someone's house and rummage through their personal possessions. You're the Warrior of Light, not the Burglar of Light).
5) Considering he's basically made the Job out of whole cloth, the 'Guild' is probably just a corner of a wharehouse with some tattered blue sheets draped over things. Most other Jobs don't even have Guilds so... what makes BLU special? (Sorry, just sour grapes there).
6) The airship docks are tiny for a reason given the usual passenger airships that players use which make up the main fleets of Highwind Skyways are the Bronco class that are equally small and just glorified flying taxis. There's nothing to explore in them really. Larger ships like the Bonanza are actually the exception in Eorzea rather than the norm. So this is completely superflorous.
7) Oh goddess no. There is already enough jumping puzzle nightmares in the game with the Sightseeing Log (especially in the original 3 starting cities) so we don't need more! (And given the amount of complaints I've seen in shout, especially that godforsaken one in Kugane, this is not popular with players at all.).