Hi enovikoff, and welcome to Tiki community!
Did you try reading the documentation first, instead of first looking in the forums?
Free Time is limited (like mine writing the documentation about WebDAV, with as much as I could understand from the feature itself and asking to coders in the devel list)
Most coders are in the devel list which is very active, and a few also active in Irc channel, and most of them use their time to code and bugfix issues in Tiki. Looking also to forums takes huge amounts of time, that not many coders have, but they decide to invest their time into looking at bugs reported in http://dev.tiki.org , as well as do some consultancy jobs, etc.
If you request for FREE support, you can use forums, read (and improve) documentation, use IRC, etc.
Regarding your question about WebDav, check that the problem is not with your OS and applications. I also tried Mac OSX when testing webdav, and I got very scarce support from Mac applications.
Get a Gnu/Linux OS instead in your Mac box, if you want or need to use WebDAV more extensively, or try using KDE from Mac ;-)
And sorry, no idea about win7 (never needed to pay for that software, and never tried it)