To get the HUD, a player must be wearing the HEV suit. In deathmatch mode, the player automatically starts wearing an HEV suit. The most important part of a rotating entity is the origin brush. It is used to determine the point around which the entity will rotate. The origin brush must be part of the entity itself.
Windows are way more customizable now.
Select any brush you want to be transparent, and turn it into an entity. The Render Amount determines the level of transparency, a higher number being less transparent. This example map has a breakable and non-breakable window. You have to tell WC where to find your .fgd files. Under the 'Tools' menu, choose 'Options'.