I'm sorry for all the flack you received OP. A lot of it was harsher than was needed. They do have a point though, so I would really look at yourself and make sure you are healthy or at least have a practical view of a 2 year old.
I know many toddlers that are just laid back. Often that is my son. He will swing and swing and swing just watching stuff. We go to open gym and he will just watch most of the time... he does have active moments, but not nearly as active as many other toddlers we know. We all joke that he's the thinker of the group and he's going to be very smart one day becuase he's sitting back taking so much in. That could be your son too, for all you know he could be gifted! Whatever it is just let him be him!!!! He's only a baby still! Let him be as long as he's not on the way to obesity he's fine. If you have real concerns about his behavior have him assesed, otherwise let him be himself. People have given lots of pratical advice, take it. If you know an activity isn't going to work, find something else. Keep the trike within a block of the house. Personally I say ditch the trike get a balance bike! They are way better! :)