You must be some kind of angel member or something, I took a chance, installed the beta version again (so far "Nothing happens" is the worst I got with the beta anyway), deleted .dat before launching DW, changed some minor parameters in the test server setting in DW site, and viola, IT LAUNCHED! And that happened like a minute after I got a notification from this post. Ha!!
Will have to update the support ticket now and then try setting up a site for real and see if it works....
Strangely, I still have no idea what triggered to launch. Maybe one of the things I changed in the site setting affected it. I'm afraid to recreate the issue though. :p