Not major issues, ask seller to repair is fine.
Roof at the end of life is mostly not repairable and no contractor will guarantee it. (1 year or 5 yr ?)
Termite fumigation is 1500-3000, termite report should tell u how much it is. (U can do it cheaper.)
Replace the old units all has a price.
Dep on how u compare with the other houses.
If u can not handle this, better back out.