I am currently riding a Suzuki DR650SE.
What do I like and dislike about it?
It's simple and reliable - The seat is a plank.
What is the most fun I can have on a motorcycle? Is it speed? Surmounting obstacles? Reaching destinations?
Going nowhere slowly. Also a bit of speed and technical riding here and there. Going to remote and not easily accessible places with a small financial / carbon / environmental footprint (compared to a 4x4). The challenge to travel light. Take your credit card and go.
Do I ride something to be admired by my friends and recognized as the best?
No one admires you or recognizes you as the best if you ride a DR650SE. A bike with hidden beauty and hidden qualities.
Do I like loud mufflers, and wheelspinning power?
No. Loud pipes are to impress girls at high school & varsity though they can be fun sometimes

. My bike has enough power to wheelie and wheelspin but I rarely make use of it.
Would I be satisfied with a smaller, less prestigious bike?
Absolutely yes. Size does not matter. I found my wife's Djebel 200 a blast.
Do I enjoy carrying a pillion and sharing the adventure?
Never really enjoyed carrying a pillion. The adventure is best shared from the saddle of two bikes.
Do I like mechanical work and "blinging" your bike?
That's what I do for a living.
Bonding with likewise riders around a camp-fire after an outride?
Yes but it's not a must. A few people and the right ones. Don't like huge crowds.
Most exciting: The next ride.