Thanks for the comments!
It's not hosted anywhere currently, but if/when it gets hosted, I'll post the server:port so you can see it.

Edit: hosted at
bzfmaps.net:7003
Yes, you do have to sit still on the escalators. I don't think it's possible to make it not do that. It works by using physics drivers + _noClimb 0, so you have to be going a specific speed.
I didn't notice you could get stuck under the escalators. I'll come up with a way to fix that soon.
You said that sometimes you don't bounce into the right spot -- if you're talking about the two bouncies in the corners, you're supposed to pick up one of the wings flags next to it before bouncing. (the wings let you drive in the air and have low gravity)
Hmmm... I think you're right about no flags. I would probably leave some flags, like one or two of each of these: N, T, SH, F, V, QT, JP, and maybe CL & ST, but remove L, GM, SW, SB, etc. I'll see what I can do about the flags...
EDIT: Now uploaded v1.1. Less flags, and you can't get stuck under escalators now.