This one sits up just fine (mine didn't come with a cabinet). BTW- I checked and mine has no set screws, so yours should just lift off.
As to the plate, just needs some oil and let sit for a bit. Don't force anything.
you have the updated version (so do I) - so far I've not found a manual for style tensioner.
Did you get any attachments? I think they are the best part, and a big reason I had to get one of these.
It's such a neat machine!