People that disagree with me stating gear check, wont save you from unskilled ppl miss one important thing: the whole discussion is about getting the functionality of a pug on par with traditional party gathering like shouting in gc. Unless you do a guild run where you know all the players and their skill you will always have to rely on good gear as a minimum requirement. There is no way to measure the skill level of a random player properly, the only way would be to add an accomplishment history, so you can see whether that individual has actually beaten that specific fp, ops or not. However doing so would encourage ppl to exclusively team up with other experienced players. And that unlocking idea is pointless, since having for instance beat EC on sm, doesnt mean you can beat it in hm too.
I agree with all your points, save for this one:
That assumption is wrong.
Fair enough. Then ask everyone in a key role to download and install either client, no big deal either. Its done in 5 mins.