Would you trust a rifle can that just threaded together? As in, the end cap threaded to the tube, and the QD mount threaded into the other end with the baffle stack sandwiched between? ? I was planning on welding the two seams, because all my current factory cans (AAC, DA) are one piece and welded together. I know my rimfire cans come apart for servicing, and I was thinking that might be nice on this as well. Obviously I don't want it blowing apart, hence my hesitation.

There are a ton of them out there built like that without any issues.

JMHO, but I would guess most factory 'tube and baffle' cans that are welded shut are done so to hide the proprietary secret squirrel baffle stack design and to keep folks with overactive booger hooks from mucking around with them and not for any strength issues  

The only issue I can recall ever hearing about is a too short baffle stack that was allowed to slam back and forth and eventually blew the distal cap off.  Build it right and you will be fine

I specifically bought a Huntertown Arms 5.56 Kestrel because it came apart - I needed to be able to dissemble and clean it because I was going to shooting corrosive 5.45 through it. Added benefit of being able to rotate which baffle is #1 in the stack so it's not the same baffle taking a beating everytime.

There's a lot of F1 cans built with removeable endcaps/mounts. No need to weld the ends, maybe Loctite if you're concerned about the mount getting stuck and the rest of the can  unscrews when you try to remove the can - BTDT

Are you worried about it blowing off the muzzle threads?
If not, how is that any different? That's an honest question.

You could always select a middle option and Rocksett it.  Normal Loctite isn't going to do much at suppressor working temps.

I did this with the first F1 rifle can I built.  I wasn't ready to weld Ti and I didn't want anything coming loose so I glued it together with Rocksett.  It's held up for years and years.