As I've said elsewhere, you have an unnatural obsession with David and you really need to tame it down. People are screened by staff and very few, especially the star struck, ever get near the VIP. Trust me on that, you can't just walk up to this kind of person. I know for fact that David has two very large dudes that are rarely ten feet away from him at all times; they WILL invite you to move back.
I'm not certain what you're referring to when it comes to people having jobs, but yes, most all "magicians" have to have a day job, magic simply doesn't pay that well and very, very few of us (even noted names) make a full-time level of income by doing this thing we love.
"Letting people back stage" isn't exactly what happens. While it's not as big a problem now days, there are always those that will boldly take the initiative and open a door and walk back stage without a single bit of hesitation. I've lost count as to how many jerks of this sort, I've had to run off or worse, have arrested. I can understand it and even forgive it to some degree when it's a 12 or 14 year old fan but not when it's an adult and especially when it's some arm chair expert that thinks he's important simply because he's got 12,000 post at the Cafe. Some folks simply don't care and think "the rules" and "decorum" are for everyone but themselves. They likewise think it funny when they break things that don't get caught until show time (don't ask).
I get really peeved when it comes to this sort and have frequently wanted to feed them to one of the cats.
Again, I don't want to come off as mean or cruel but you do need to come down to earth before you set yourself up even more, for hurt and (no pun intended here) disillusionment.