Yeah that would cause some tuning headaches. You need to get that exhaust rigid mounted in the rear or it will keep breaking things up by the head. Trust me, I've been there not too long ago. Now that I added rear mounts it's been perfect.
Yeah that rear frame cut need a horizontal brace, and you either need longer shocks with the seat like that or need to add a divit for tire clearance. If you hit a bump and those shocks fully compress, that tire will be saying hello to the seat pan. You need new rubber too, those tires look tired.