As far as a phantom center goes, the right and left speakers should be equally distant from the screen (which you want anyway), and you should sit directly in front on the screen (i.e., equally distant from both speakers). As for toe-in or not, that depends on the particular speaker, and is not a question of whether there is a phantom center or not. First consult the manual for your speakers for suggestions, then the manufacturer's web site. Or just try it both toed-in and straight out into the room. Most speakers are best aimed at you or nearly aimed at you (either with a little less toe-in than directly at you, or a little more toe-in than directly at you), but not all speakers are best that way. Normally, tweeters should be at or near ear height. Again, this can be somewhat variable, but it again has to do with the speakers, not whether you have a center speaker or not.