Just include these lines into your config:

seta image_downSize "1"
seta image_downSizeLimit "32"
seta r_skipBump "1"
seta r_skipSpecular "1"
seta r_skipNewAmbient "1"
seta image_ anisotropy "1"
seta r_multisamples "1"

Experiment with downsize limit to determine what is most suitable for you. Values lower than 16 is not practical though, cause Q4 does not have r_nomip command, so rail, shaft and rocket effects will be greatly affected.

http://ucguides.savagehelp.com/Quake4/FPSConfigs.htm

Be careful with that link: http://www.q4max.com/wiki/index.php/Locked_Cvars

or use the performance preset in q4max :)

Yeah its the easiest thing to do, and you can tweak it (brightness etc) in the menu. From there if you want "picmip" textures you can just put these into your quake4config.cfg (at the end of the file, or find and replace the values):

seta image_downSize "1"
seta image_downSizeLimit "32"

Then if you want the same settings in q4mp just copy the quake4config.cfg from the q4max folder to the q4mp one.

www.fojji.se + image_downsize 1 + image_downsizelimit 16 (or what value you want)

would kissing you be a crime?