No, Milkshape3d isn't a great app for making levels for games since it does not compile to BSP. It's more of a low level modeling/animation tool for game characters. I don't use 3d studio max so i can't help you there but for creating bsp files for pro (I can't say for certain though, I use v113) grab a program like Quark or Valve's Hammer (New version of WorldCraft). [href] www.planetquake.com/quark[/href] should take you to the quark page but I don't remember the hammer page. Hope that helped a tiny bit if at all.
My Specs: p4 2.2gig, 786mb ddr ram, 120 gig hd, Geforce4 128mb ti4200, WindowsXP.