You can test it by simply pushing the shoulder up, and if it moves up then she has shrugging shoulders. Chances are this feature is an extra though, I know I had to pay to have it added for Regina even though she has the latest skeleton on the market.
I've looked at the photos on Cloud Climax of Alexa and none of them show her shrugging.
However to do what you did with her hands up, it should be NP. Yes the instructions will say not too but that's just to cover themselves. These dolls are quite tough in moderation, as long as you take them out of the extreme positions after the shot and don't leave it too long. Looks at some of Psion's pics and see what she is capable of... remember the power one where shes climbing on the kitchen bench
http://www.uklovedollforums.co.uk/fo...ad.php?t=14376
Anyway she's your girl and you can only do what your comfortable with.
BTW you should see what I put Kimberley through, and she has a basic skeleton and prob basic TPE. But she is a tough cookie! You can't really tell but in one of the nudes she has crossed legs sat on the bench. That's her legs as wide as they go to achieve it. Not for long though, a few minutes.