My H never truly moved out during our whole D sitch. He was scheduled to be deployed and, therefore, wanted to stay in the house to be w/ the boys until he left. He did leave 2 different times, but only for a night or 2 each time.
Anyway, I can understand your concerns, and I will tell you up front that it also truly sucks having the H who wants a D in the house all the time. At times, I was so exhausted from trying to constantly keep up a 'front' that I was 'fine' w/ all of what was going on.
But, after saying all of that, I guess I would have to say that there are good & bad things to your H staying in the house as "friends." First, at least he is not "gone" and maybe finding out that he really does think the grass is greener. Secondly, he will be there all the time to be able to see first-hand the changes you are making in yourself and see that they are not just for show and not just so he "may change his mind."
Unfortunately, until he finally figures out what he truly wants, either to work on your M or actually D, you are in limbo. Either way, whether he is living in the house or not, it sucks for you, but like I said, at least w/ him there, you have the constant contact and he will see what he would be missing on a daily basis.
Me: 38 H: 35 S4, S5, S10 Bomb 01/07 Wanted D - nothing would change his mind Numerous A's prior to D bomb; EA prior/during D bomb Piecing 04/07 Deployed for a year 05/07 Still Piecing 2010 M 11 yrs 05/10