the all wood self bows will loose some performance if left strung or shot a lot..they'll take a "set" and stay in the strung shape. I've taken several deer with recurves and long bows older than me, just watch for stress lines, cracks, deliminations and such and you'll be fine. If you pick up an old bow that you know hasn't been shot in years, string it at a low brace height, and exercise it before shooting it all out.
Most bowyers recommend the arrows be in the 8-10 grain per inch range...it will help your bow last longer and make it much more quiet. Yes, too light of an arrow will make a bow explode..i've seen it on the range. Carbon your best bet is add tip weight, different points or brass inserts, so on.
Have you bare shafted your arrows or paper tuned them? You shouldn't need feathers if your arrows are tuned properly, until you shoot broadheads..all feathers do is help stabilze the arrow faster (flex recovery when released).
As for the arm slap turn your wrist in on your bow arm..(like your picking up a heavy suit case) it will eliminate string slap, also your string brace height may be a touch low.
Looks like an awesome bow, but man you need some primative arrows to match...those carbons just don't feel right, lol! I don't know what the shipping would be overseas but I'll see if I can scrounge you up some cedar shafts, and fletch them with some wild turkey feathers.
Enjoy your new toy! And make sure you get someone else into archery especially the kids!