Every shop or serious mechanic should buy this set. It has saved me so much time and money dozens of times. Just go slow with ~~carbide~~ cobalt drill bits, they shatter easily.
It's spendy, but the Irwin Hanson 11135zr set is everything you will ever need. I use the hell out of my set and have a near 100% success rate*.
*the one failure was another tech didn't realize they were left hand bits, so snapped one off trying to force it to drill.
You ain't a tech unless you have one of these in your box - https://www.amazon.com/gp/product/B000EEX644/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
Screw extractors work wonders with broken nozzles, as well. I'm sure you can find a smaller/cheaper set, but I used these: https://www.amazon.com/gp/product/B000EEX644
I'm sure torching it is fine, but I have never had a bolt/screw I couldn't get out with my Irwin Hanson set.