I just got the Predaking reissue, and put all 5 predacons together.  The arms seem to be impossible to rotate, and I don't want to break this expensive toy 1 hour after I open it, so my dumb question of day is, are the 2 predaking arms rotatable (up and down)?

 

:tfevil

Yes, they're probably just stiff. But do be careful, way back in the '80s, I was lucky enough to get all 5 Predacons for Christmas one year. Within the first hour, I snapped one of the plastic tabs in the socket where one of Predaking's arms attaches. It still all assembles and such, but that one arm is still loose to this day.

Smartest thing to do is keep Razorclaw's arms extended, allows the arms to be further out and make use of the shoulder guns.

yes, just make sure Razorclaws arms are pushed into his chest while they are merged.