Lancelot- I will give it a go on answering your questions.
Hung up on things? I don't mean to sound degrading, but, No, I haven't noticed as I try to keep things away from the trigger area. I feel that the mag and pistol grip protect the area fairly well. Due to the extended "Mag clip" or potrusion on the mag that engages the mag release catch, then an inadvertent mag drop is fairly easy to avoid. There is a bit of travel that still must be done to release the mag. My SAR 2 is broken down awaiting some work to be done to it, but, here are some pics:
Baseline photo
Extended mag depressed to point to release mag catch
Scrape fingers or hands? The edges aren't sharp to me, so I would say NO.
Screws or Rivets? I would go with rivets, as they are simple and once done (correctly) you can forget about 'em.
2002GTI- It may be butchering a healthy animal, but if you want it without the other side, just dremel (or hack-saw) cut it off & smooth the edge.
I really like mine, as it is a simple yet functional modification. IMHO.