Well, it sounds like your hubby is more extreme than mine, but my DH is super squeamish, very clean, and hates needles and IVs. Honestly, I'm the same way. But we both did great about all of labor. DH had even said he wanted to be up by my head the whole time, but ended up holding one of my legs while I pushed and saw everything. He was great - up until it was over and the OB told him to announce boy or girl and it hit him like a brick wall, lol. He sat down for a few minutes while things were calming down and then he was fine again.
RE: common hospital policy, it really depends on the hospital. There is no "common" right now. At my hospital, a hep lock is "required" (could probably refuse, but it would be a battle at that point) but an actual dripping, hydrating IV is not used unless necessary. They allow clear beverages at any point in labor but not eating. My labor was short, which helps I'm sure, but I had no issues with dehydration. Call and ask - and also make sure your doc has the same opinion. Some hospitals won't require an IV but the doctor will.
And a doula does sound like a good option for you to mediate. Also, get your DH to do as much research as you are so he's comfortable with interventions, when and why they should be used. Basically eliminate his fear over things so he can help you make the most informed decision possible in that moment.