You've already got a pretty good sized generator with that 5,500. The hybrid function may not be worth much too you. If, for instance, you had a 2,000 watt gen and had an AC unit that ran at 1,500 watts but took 3,000 to start the hybrid would kick in briefly to let the little gen start the AC.
For your situation, yes, I guess you could use the hair dryer or MW with the 2 ACs going using the hybrid feature. Both of those appliances would be short duration use I would assume so they wouldn't deplete the battery bank too bad.
I agree, trying to use it to run 3 ACs at once is probably not a great idea. I don't know all the numbers on the ACs and your generator so it's hard to say. If the gen will carry all 3 but not start the 3rd when already running 2 it might work out.