Compared to what? What did you use as a reference for checking the angle? How do you know it is incorrect?

This gets really fuzzy when dealing with an ARF. You have no information on incidences or thrust angles, no drawings, no plans, nothing. If you are lucky, you might find some information someplace but it is unlikely especially on some of the off-brand stuff like Phoenix.

I'd be careful on the engine thrust angle unless you are sure it needs it. One good way to tell is by flying at full throttle then quickly pulling back to idle. Does the plane quickly change in attitude? If so then thrust angle might be an issue. If it just keeps flying forward and slowly descends then there likely isn't a problem.

What about your CG? Are you sure it is right? Have you tried moving it forward some to see if the handling is better and if the plane doesn't want to climb so much? It might be worth a try.

Sure, it's possible something on your plane may be out of whack. It does happen on ARF's. Just be sure though. I'd try working on the trim first. There is a good trimming chart on the last few pages of this manual: http://manuals.hobbico.com/gpm/gpma0400-manual.pdf