Given that anyone can create their own one-player squadron, I'm not too concerned about them being limited to squadrons. I already have one, with 3 members: my main CMDR and two alts (my "assistants"). Nor am I concerned about them being excluded from Solo mode, as I have my own Private Group (and surely they'd have to cater for PG's).
There has been some mention of a minimum number of squadron members to get a Carrier, but that's easily fudged by players temporarily joining each other's squadrons to get the numbers up (we've already been told that you only need one person to keep the Carrier). I will join those offering to do this. Hopefully Frontier will see that this restriction is unworkable.
There was also some talk of a minimum crew required to operate a Carrier. I hope we can use our NPC copilots to meet this requirement (we're allowed 3 per CMDR, after all: with my 3 accounts, I could muster 12 crewmembers). It would also be daft not to include multicrew in this. I can't honestly see any justification for needing more than about 4 (Command, Helm, Navigation, Engineering).
Which leaves refuelling. I'm hoping they either run on hydrogen fuel, or on something that can be synthesised onboard from hydrogen fuel: a T9 or Cutter with an 8A fuelscoop and a lot of extra tanks could gather a heck of a lot of hydrogen. Using mats will run into a credibility problem. If vast quantities of materials are required for every jump, demand will be such that commercial mining of such material will become economically viable in any semblance of a sane economy, it will become impossible to explain why you can't buy fuel with credits.