OzMo knows what he is talking about, you would do well to listen to him! Don't go by visual clues after a repair to see if your plane is straight, measure it out and be sure! 90 degrees means 90 degrees, do whatever it takes so that it's correct. Investing in an incidence meter and a number of steel straight edges is money well spent.

Is a twist in the fuse a big deal? Yes, most assuredly. I would not fly it like that. Certain things in RC flying can be by choice such as prop selection, color scheme, type of wheels etc, but other things are laws of physics and must be followed like it or not. Proper alignment of flying surfaces relative to the wing chord, twist and warps, and thrust lines are non-negotiable and must be correct regardless if the plane is a trainer, large scale, or 1/2A.

Spend a little time fixing it correctly now and fly with an untroubled mind.