i respond cause its hard not to when you have someone acting quite blantently annoying ... i have to atleast put this annoying questions out of my misery
if your used to writing your own formats... then do so now - no one is forcing you to use BSP.
that aside i'd hardly call TME a world format - its more like an active scripter for worlds.
if you want to use BSP the source code for all version upto 53 (Quake3) are available form id software...
you can use textures you create yourself, however the ONLY editor which you can build a world on without requireing the games is Qoole '99 (which is a bloody task in itself to find on the net in working order)
Worldcraft 3.x can as well, however Worldcraft 3.x isn't exactly the best tool for jobs like developing complex worlds... but that said niether is BSP.
if you are as much of a programmer as you think you are, look up on the net about BSP not the editors - as perhaps you'll learn if it would be worth using, and if not maybe the format could give you idea to code your own with an editor to suit your needs!
Tsu'va Oni Ni Jyuuko Fiori Sei Tau!
One block follows the suit ... the whole suit of blocks is the path ... what have you found?