Towing - GCWR is 15250 lbs, and GVWR is 11030 lbs. I tow a 4600 lb Wrangler with my 2018 Navion 24V. I keep the Navion weight under 10,600 lbs, and keep the towed weight under the 5000 lb hitch rating, and no problems.
Finding service away from home is a **** shoot for any RV these days. Just as many threads out there for "can't get service for my Ford class C" as there are for Sprinters. And some of that is at home. Check around where you live, and ask the local dealers if they'll work on whatever you plan on buying, before you buy. You may be surprised.
Do a search on gas versus diesel class c, and you'll find a few threads. It's one of the most popular topics on most RV forums. There's usually some good feedback from Sprinter owners on them.