1)wonder what she must have thought when she seen him just stripped down to his swim trunks?
She probably thought that was going to make a very adequate meal.
2)Given the situation I imagine that the guy thought he was g oing to get lacky and might have become aroused at the rought play to start with?
Yes, at first, but once he couldn't breathe, he got worried.
3) Would she think that’s she is going to get a good feast ou of what she can see buldging in his swim suit?
Yes, she did, and she was very hungry.
4) When she gets him on the shore and start to remove his swim trunks , could he still be aroused?
No, because he was unconscious at that point.
5) Would she remove his private parts all in one go and eat them that way?
She would remove them all at once, and then bite off chunks and chew them.
6) What she do with his swim trunks and outer clothes?
She jsut left her victim's clothes with them, lying in their blood.
7) What would anyone coming to the lake for a walk find in the area of her feast?
They would find the disemboweled body, with internal organs and genitals missing, a gaping hole in the abdomen, and blood-soaked clothes nearby. I'm sure the person would run back to town very quickly.