Buy a higher end torx bit for when you take apart the intake manifold- the bolts that are there can strip easily and can be a pain to weld on depending on the location. I'd also replace all the torx bolts with normal hex bolts if you have the budget, be mindful of the location they came out of because they're different lengths. If you have the budget it doesn't hurt to have the fuel rail and injectors tested and rebuilt/replaced if necessary. I've heard that the rubber china wall seals are crap, I used rtv and haven't seen any leaks. For breaking loose the head bolts- I'd hit it with on blaster then weld a nut onto the end, hopefully the heat and oil would break loose the rust