So you basically have had the same experience I have had with mine. Of course all of us are just getting started with them.
On the T-10s, I'm ok with them, I would have preferred to see them all around. Why the other screws are Pozi (they are not Philips), and those are torx, I don't get.
I haven't had a toothbrush (thats what I call them), fall off, but it does get a bit awkward because of the mix of quick pins and threaded joints. I think they did the threads on top so they get tight and you can adjust. But I really wish for the storage spots they had a quick pin and a hole in the toothbrush. It would also help figure out which way around they should go, brush up or brush down.
I like the idea of 4 locking casters.
I'm still trying to work out the flip move. I had thin material which wouldn't lay flat, so it wouldn't get "caught" on the flip up catches. Also still trying to figure out how to gauge where to flip, if you are to close, then you end up like you did dragging it. I tried it with the arms in, but then you basically drop the table, but with them out, then it's hard to access the casters to lock them.
Overall, it's handy. I can see having 2, one to unload material onto, and move that around, and a second you slide material your cutting onto.
It definitely can be unstable, but that's just a fact of how it is when compact. When it's down low, not so bad, but moving it around in the work height, folded would be bad. If I were to move it up down stairs, I would probably remove the tooth brushes just to save some weight. It's definitely compromise of different things.