Lame. All of that stuff you listed is just playing the game and having fun. You're not unique at all. I do find it weird, though, that you specifically said you only enjoy the races, but then listed a bunch of stuff that has nothing to do with racing. lol
You can't shut down LSC permanently. Only for a few minutes, at least that I'm aware of. So if you're driving all around town, by the time you get to the next LSC, the last one is probably okay. So you're not really accomplishing anything at all.
Personally, I think taking a personal vehicle underground is a waste of time. All the guy has to do is call his mechanic to bring him another one. If someone did that to me, I'd just laugh at the time he was spending doing it while I just grabbed another car. It's not like I won't get it back by going to a mission and coming right back ... and I believe that kicks you out of the vehicle. And, of course, I can wait until you've driven for a while and just kick you out myself.
Instead, I just try to shoot all four of their tires (if they're not armored) and then leave the area. They can't call a new car because that one's too close and driving it becomes very difficult.
The cargobob thing is pretty dumb, too. I may be wrong, but if you picked me up using a cargobob ... which ... you know ... good luck in my 9F ... I believe I can still use weapons. Which means that I could pull out a sticky bomb and destroy you in the air. But even if I can't, I'd just wait until you were high enough and then parachute out. If you dropped my vehicle and destroyed it without me in it, you'd have to pay for it and you'd get a bad sport warning.
And who uses an ATM? lol
It's very clear that all of the players you're griefing are simply noobs who haven't figured out how all of this stuff works. So good job, man. Good job. lol