HgLab requires at least SQL Server 2008 and pays no attention to Service Pack levels or updates.
With ports, here's the situation. By default, HgLab uses standard HTTP(S) port both for the web interface and to communicate with Mercurial clients. To talk to SQL Server you need to have port 1433 (which is the default port for SQL Server)open on the machine running it.
As for requiring SQL Server at all, you have a fair point here. HgLab does need at least some kind of persistence mechanism to store all the information (Users, Teams, Pushlog, etc), so there's that. Requiring a full-blown SQL Server even for the Evaluation does sound like an overkill, which is why I'm planning on adding support for SQL Server Compact or SQLite, which do not require installation. No ETAs, though :)