As usual, a lot was left out.
Your friend, how much boating experiences has he had? During our 8yr Loop we encountered whirlpools on the Mississippi. Would he know what to do in that case?
Does he know rules of the road? The tows will not be understanding if he causes issues while confronting or trying to pass without knowing what he/she is doing or what the signals are.
Does your friend know 1st aid and how to perform it on himself? To me, that would be the biggest issue with a singlehanded trip, an accident that incapacitates you.
BTW, we don't have thrusters or a generator and did 1/2 the Loop before we had solar installed.
The Loop is not an easy trip, very beautiful, exciting and dangerous.
We did our Loop in stages, cruising from May to Oct and that allowed us to really see the trip and experience a lot of what the fast cruisers miss.
PLUS, it is nicer if you can share it with someone who can assist with lines, etc.
IF you need and would like to have a crew, try Find a Crew.com and see if you can find someone to join you.
Goo luck.