The ACA "pay" for leading tours is more like a volunteer compensation. The last tour I led in 2009 it was $50/day plus the tour, food and also re-imbursement for getting home from the trip. I don't think you will consider that "a reasonable amount to live on" beyond the duration of the tour itself. Certainly not if you are paying rent, taxes, mortgage, or in your case RV expenses while on tour.
ACA leaders are not employees but at $50/day it's hard to consider oneself as a serious "contractor". We sign a contract with ACA that states that they will not hold us liable for unforeseen events however that contract does not cover any future problems between leader and individual group members. Leaders are expected to be good enough mechanics to get a rider to a bike shop. Often this requires road side wheel removal and brake work, thus there is some risk leaders must assume hoping the rider doesn't have an accident resulting from his/her mechanical work then holding them personally responsible. $50/day does not pay enough for leaders to have private insurance unless they have income from other sources. That said, I've never heard of leaders having legal action taken against them by participants.
If there are any ACA Tours staff in the audience, please correct me if the above information has changed since 2009.
Day to day? You share the same wonderful trip as your group is experiencing and the camaraderie of that group becomes intense on the longer tours such as the TransAm. After dinner you can't relax as much as the others as you need present a brief summary of the next day's ride and you need to be constantly on the phone planning ahead. You also need to enter and balance the day's expenses into an account book. There is a certain level of stress being on duty for 93 days continuously.