All my yep.
Although the result would still technically be the Thing, as it 'becomes' it's prey, so a fusion would be in the Thing's favor.
Unless it got dominated by the hive mind. A human-xenomorph hybrid is still a xenomorph. There is still the possibility such a hybrid would be independent from both species and kill both.
Also, we don't know if the Thing can or can't absorb other forms of life, ie silicon based, though I consider it likely.
Silicon's pretty common so that's quite likely.
Not sure about the hive-mind thing, but if it assimilated an Alien, it could concievably build it's own hivemind. Admittedly it would be small at first, but it's intelligence and ability to build a spaceship out of spare snowcat parts
If it could build its own hive mind it would already do so, unless it finds it disadvantageous (possible). I like to think the thing we saw - was a fragment that rebelled against a larger hive mind biomass, hence why it is ALWAYS autonomous, even where highly disadvantageous (blood tests much?).
- also, there's no way that could be airtight
Why not? It'd just be like a massive deadly oyster with more teeth and acidity.
Actually, the Thing with Xenomorph capabilities would be fucking terrifying, as it would gain immunity to fire.
Xenomorphs CAN adapt to extremes. Not all of them do
That plus other things means it could attack directly rather than be sneaky.
Xenomorphs are smart. They'd stay the fuck away from anything that even reminded them of the thing - and with the hive mind, they would know if it was trying to imitate a Xenomorph.