[Raptor]

Keep in mind that all the holes I created were flared afterward which makes them stronger than flat untouched sheet metal. If you do one without the other, you will take a lot of the support out of the panels.

I would leave the brace between the towers in until the cage is in place, then cut it out after. Basically any thing that could effect the geometry of the car shouldn't be removed until there is a replacement (cage itself).

If you are gutting it to prepare for a cage, the best things to focus on are going to be the sound deadner (on bottom and top) and painted surfaces where the welds are for the attatchment points of the cage, that stuff catches fire and could make for a bad day if it can't be put out in time. It also has nasty effects on the welds themselves and could make the integrity suffer.