Welcome to the forum. Two years will give you some good research time.
B vans are truly great for ease of driving and parking almost anywhere, with excellent fuel economy as you already know. We've had one for more than three years and a lot of miles, and couldn't be happier.
I think vans are great for one or two people.
Floor plans vary a lot. If you want to bring one friend at a time, look for two seats only up front, which will give you more living space in the back versus a three or four-seater. You can find twin bed options if you don't want to share a bed. Ours came (used) with twins, which can be converted to a larger bed by inserting two table panels.
If you think you will seriously travel often with two friends, you might want something bigger like a small class C. In a van, you'll have to be sure you have the extra seat belt, possibly on the rear seating area - not all vans have them. Sleeping for three adults is iffy in a van, comfort-wise and space-wise for everybody's stuff. Some people bring tents for sleeping area for extra passengers beyond the first two.
Different strokes for different folks, of course, when it comes to layout. I like for the bathroom to be on driver's side and galley on passenger side next to the sliding door. That way you are facing your outdoor "living room" when working in the kitchen. This layout often also gives a window and counter where you place groceries, put plates of food, etc. as you come and go from your "living room" on the sliding door side.
I am also a fan of having the refrigerator and microwave at mid/eye level rather than below the counter, to avoid stooping down when you are searching the frig. I also prefer a fully enclosed bathroom/shower rather than aisle shower floor plans.
I like lighter color woodwork; and an open layout where you can walk into your van and see straight through to the back (versus a lot of hanging cupboards that can create a sort of cave to the back.)
If you can, have a screen for the sliding door - some makers now include this built in, or you can attach one with Velcro. Some vans also have back door screen setups.
All of the above is subjective, just one happy B person's input.