Are collagen injections safer than other dermal fillers?

Is this what is injected for larger lips?

I had a type of bovine collagen filler for my marionette lines, minor lines above my upper lip and to raise my cheeks. My lip and area above are too big. Also, there are lumps on the top of each side. 3 months post-treatment, my smile has turned into only a joker smile or one in which my upper gums show. This recent change is upsetting. Is my only hope to have it dissolved? Does this happen to others sometimes?

Can the skin not produce collagen? Can you deplete the skin after years of collagen treatments?

I have lost weight and have very thin, loose skin on my arms. Will collagen treatments cure this problem, and "shrink" my arms back into shape?