There are several other ways to earn Grand Company seals, including but not limited to: supply/provisioning missions, certain Duty Roulettes, and farming dungeon drops to trade in - thus invalidating points 7, 9, and 10. Also, using FATEs to level your chocobo is far less efficient than something like grinding up in Urth's Gift.

To be honest, I think FATEs are fine for events, seasonal or otherwise - the quest chains don't last nearly long enough to make FATE hunting a serious issue. Personally, I was okay with using FATEs for Atma/Animus relics - considering nobody really grinds FATEs to level any more (doing your hunting log and a handful of guildleves is a lot easier for getting from 1-15) it's a reason to go out in the world - small as it is - and take in the sights. I do agree, however, that SE's going to need to be much more creative on how they're going to continue making the overworld somewhat relevant, or else it's going to get dull, and fast.