I don't think this subject has come up before. I personally don't recommend that the throttle bodies be disassembled because of the things you're running up against, although if badly corroded, you might now have a choice. When re-assembled you have to be absolutely sure that the butterfly screws are staked/locktite'd so there's no possibility that they could back-out and be injested by the cylinder.
If you're about at the end of your ideas on removing the stuck screws, consider taking it up to a good machine shop and see what they can do.
While it's easy to do, I recommend you change the small seals at the end of each shaft.
If you're about at the end of your ideas on removing the stuck screws, consider taking it up to a good machine shop and see what they can do.
While it's easy to do, I recommend you change the small seals at the end of each shaft.