Quake 2, like Quake 1, needs a source port to be playable in widescreen and on modern computers without problems. I like KMQ2 for a straight port, but I've been unable to find working links to that. I like Quake 2 Berserker for the graphically overhauled version http://berserker.quakegate.ru/. Be aware, the site is in Russian. You have to download the q2bers_base.rar and ALL of the updates. You will need to do a complete install of the original Quake 2 game WITH the videos. It may not work if you don't. Then, you have to unpack the Berserker Base program into the Quake 2 directory and then unpack the updates into the same folder one by one in order from earliest to latest update. Each step is essential to get the game working. I also recommend downloading the high-res textures to make the game look better.
To disable the hud in Quake2-Berserker (or other Quake 2 versions), open the Quake2\baseq2\autoexec.cfg file and enter the following commands:
(Note, the values that start with rfx only apply to Berserker. They get rid of effects that mimic hud overlays, like a gas mask).
The scr_draw2d 0 is the command that disables the hud. It can also be applied through the console, but will reset each time the game is started unless you add it to the autoexec.cfg