I believe I now have a resolution to both issues: idle/stalling and vibration.
Of course, I'm hesitant in stating everything has been resolved.
Thank you everyone for reading my lengthy bs and stupidity and providing suggestions and info.
A fbbo member also provided a specific part in the carb to check.
I realize some probably called out these issues earlier, sometimes it's really difficult to see the forest when all the trees are brand new or just rebuilt!
I like using the kiss principle, which led me to swap 1 motor mount a few days ago, even though both are brand new, I checked them multiple times, removed one once too.
The old one is brick hard, when I pulled the new one it didn't fall apart, it's not ripped or destroyed, I put it in a vice and it doesn't compress, it doesn't twist, nothing.
See if you see a difference in the before and after glass of water test.
Carb: I pulled the tubes out, air goes through no problem, WD40 too. Same with the hollow bolts that hold it down.
Then I noticed what appeared to be tiny threads clumped on one screw at the top 'port' just below the head.
And I mean tiny, stuck there, air didn't blow them off. New cheap toothbrush and some more cleaning/air, done.
Put it back together, idled fine. Took it for a ride, no stalling. Ran on when turned off, lowered idle screw, fixed.
Smells a tad rich, so I'll check the timing and idle mix screws in a few days.
If the new rubber mounts are that crappy, and poly mounts are expensive/unavailable, I've got a number of old mounts I can use, a few actually look very good. Plus I got a nowhere to be found poly trans mount from a fbbo member.
New parts that suck and you don't know it is the worst!
Now I need to solve the clunking only during a right hand turn issue - another thread.
I will update this again once I swap all the mounts, so we will see if that stops the vibration.
What do you think, do you see a difference in the 2 videos?