I don't know about the changing the locks.... if you have a good reason for it perhaps.... On the other hand, you may want him to be able to come in and wait for the kids if no one is around. Also, you might want to leave the house looking real homey when you aren't there... and perhaps fill it with photos of you and the kids (I took away all the photos with my H and replace them with current ones of me and the kids doing really fun things without H.... that way he could see what he was missing! ;-) Another idea, leaving some beautiful roses with a note, "Because you are beautiful" and sign some guys name. Hee hee!!!! Of course, if he asks you just say it's some silly guy who is just a friend. Nothing serious... because, of course you don't date!!! Until a divorce is final you wouldn't be dating.... you don't feel it's respectful for marriage or anyone even interested in dating you.... but gosh, it sure is fun looking...
Does he have stuff in the house? Is there a reason he may want to come in to get something when you aren't there? What you could do is change the locks and then let him know there was a problem with one of them and rather than get it fixed the guy told you it would be cheaper just to replace them all... or something like that (I did this by the way!), and then tell him, "Since you aren't living here anymore I'm sure you don't need a key...." and then leave it at that.
I wouldn't answer the phone if I were you. Go a little dark for now and see what happens.... If he leaves a message wanting to speak with the kids, then have THEM call him back.
As for you... go shopping. Get some attractive new clothes, get your make-up done, nails done, a new push up bra (in red and black), thong underware (in red and black).... have fun!!!
(P.s. My husband used to get angry about money too. It's important not to change your spending habits too much because this will be used to help determine child support and any alimony if you are entitled to that. Start keeping all receipts and outline monthly expenses. Another thing, you might consider having the kids ask dad to pay for the expensive things they need. That way you aren't in the middle of it and he can't blame you for that).
There is no arriving, ever. It is all a continual becoming.