I would challenge that point of view, assuming you have a normal(ish) bite, and don't have too many parafunctional habits like biting nails, opening hair clasps etc, then I would not expect a Maryland to fail if it's done well.
I've had one patient who had cerebral palsy who had one in exactly your circumstances, he fell over unfortunately and knocked out the supporting tooth, with the Maryland still attached to it!
We finished up making him 2 Marylands to replace the 2 missing teeth, as far as I know he's still doing fine with them. He actually turned down free implants because he was happy with the Marylands.
No, you wouldn't get the tooth pulled out by the impression, it's really not that easy to remove even very loose teeth. If you were worried about it though, a small smear of vaseline over the loose tooth can help.
There aren't many other options, a conventional bridge would be difficult to do since you'd probably need 2 GAs fairly close together, one to prepare the bridge and one to cement it on, which is a bit more risky and couldn't really be justified for a purely cosmetic procedure (the 2nd one).
If you had enough support, could you tolerate the dentist removing the temp crown from your front tooth and cementing in the bridge? That would remove the 2nd GA, although I don't know if your PDS will pay for it?
The only other option would be to get a denture made during the GA, then see if you could work with your mental health folks to learn to tolerate it? At least for short periods when you were wanting to be sociable?