1 - 3: Yes.
4: Once your Configurable ODBC DSP is set up, you'll be able to search for users in that directory the same as you would in AD. You can then use the Add Users button in Section Access Management and simply select your new DSP as the directory where you want to search for users.
5. The v11 server reference manual is kind of useless for this (and for most other things too). Check out the old v10 reference manual at page 253. This post also seems pretty good: http://community.qlik.com/thread/31302