Unfortunately I cannot use vhost template feature because of the existing directory structure on our servers.
I could easily live without the webadmin interface since our servers (and apache vhosts) are managed by software almost entirely written by me, changing some part of software is not a problem. The question is: how to tell LSWS to listen on the right port without access to the faulty webadmin (I've tried to alter the httpd_conf.xml: changed *:443 to *:8088, and disabled SSL options but with no effect - LSWS served only the welcome page), or how to use the apache configs directly (still I'm afraid that LSWS would listen on the SSL port rather than 8088 or 80).
This is only a hint for you: 3800 vhosts is not a record on our servers, some time ago we hosted about 7500 domains/subdomains on a single webserver. I would like to know if there won't be any problem with this in a future.