My best friend/maid of honor will be doing my makeup and her own for my wedding. But she does not want to do everyone's makeup as it will take too long and she does not want it to get in the way of anything else she needs to do as MOH. Do you think a MUA be okay with doing everyone but the brides makeup? It would still be around 6 people with bridesmaids and moms.
I would reach out to some HMUAs for quotes, and to verify that information. But, in my experience, none of the HMUAs specifically stated that services had to be provided to the bride; only that a particular number of services had to be scheduled.
Yes, I don't think this would be a problem - like the others have said, it's usually only a minimum number, not a requirement the bride also be a part of the deal. Someone mentioned once how she had separate makeup artists come to houses for her mother and MIL and another separate person for her and her bridesmaids, so I'm pretty sure what you're asking is common!
I don’t see it as a problem. Make sure whomever you hire is able to bring along an extra person to get everyone done on time. It’s common for hairstylists and makeup artists to bring along a coworker or two when you have large groups and not a lot of time to get ready.