Only the big bolt just behind the radiator on the subframe holds it (not counting the small face bolts). Make sure you get the forward one not the similar big bolt to the crossmember.
As for painting, wet sand the car with 320 grit and then 600 grit wet/dry paper. Any defect, ridge or bump you can feel with fingertips is going to be seen through paint. Sand out all scratches and cracks in paint. If you feel an edge, sand some more. You can get things nice and smooth in short order. It is really not too hard. Spot prime if bare metal shows.
With compressed air and a paint gun you can apply paint very nicely too, although it helps to see that done. The Volvo paint code (130 for the GT silver?) can be made up at any auto paint supplierDust is the enemy here. I just put a nice fender on the kid's 850 and sanded the scratches out of the spoiler (glancing blow to fender and spoiler) and painted and clear-coated it. It came out very nice and it was my 3rd car painting experience. Air tools, good gun and quality paint make it surprisingly do-able.