How many string gauges could you go up or down without the intonation changing. Such as going from 10-14-22w-30-38-49 to 10-13-18w-26-36-46. Would this change the intonation or cause any problems. Thanks
Any change in string gauge will result in a change in intonation. The question is would it necessarily require an adjustment? Even if changing only a few strings like your example...Personally for me...yes. And likely a minor truss rod adjustment as well.
Different string gauge results in different tension on the neck. The truss rod pressure counters thr string tension it's kind of a balance. So unless you have an usual neck your going to have to adjust for different string gauges.
Sometimes you don't even need to mess with the truss rod. If your guitar is setup with 10-46 in standard tuning you can go down to a 11-49 set in Eb without anything more than maybe a minor intonation tweak. 10s in standard and 11s in Eb tuning have the same amount if string tension.