hektikpazermat_antialias 0 mat_forceaniso 0
Don't set these to 0. The minimum value of these cvars is 1, and setting them to 0 will just cause a material system reload = breaking mumble overlay/increasing game startup time. Think about it: mat_antialias controls the number of samples taken per pixel on your screen. If you took 0 samples per pixel, your screen would be entirely black :P
Reading directly from the game's code, the same hardcoded minimum exists for mat_forceaniso:pConfig->m_nForceAnisotropicLevel = max( mat_forceaniso.GetInt(), 1 );
If setting mat_antialias to 0 is harmful, why does my game tell me it's the default?
Because the values of these cvars are loaded as part of the material system config that is stored in the registry. They arent loaded and stored like normal cvars.