I don't think you will really know until he tells you that he wants to be with you again. There are some positives and at least in your sitch there is some progress instead of complete back peddling by my H (I remember last year at this time he saw S three days a week and now maybe once a month). I do think that you need to do like your dad said and start setting boundaries with H. It seems that he is less tired when around you, probably because he is sleeping better at night, but you have to start now letting him know what you expect so it isn't sprung on him. You don't have to be mean, but ask H to get off the computer to play with S or help you is not mean. You can say it nicely.
Really think about what you want out of the R and who you want him to be because as his mind heals, you need those expectations to be set before he learns something different and those connections are made in his brain, but also so he doesn't feel you changed your expectations all the time. Set them to what you want and try not to settle for less, at least when he is around you. Like he needs to be with your parents for a bit or be with H and not on the computer. Don't be his mother, but tell him nicely, H please come play with S while I do... or H please feed S while I .... or H please watch TV with mom and dad for this show and then we can watch something else together in my room.
Just some thoughts, but you are still doing great! 1/2 the year is over so who knows what will happen with the second half.
Me29 S3 H left 4/1/09 I file 8/2/10 Divorce final 5/17/11 1st http://www.tinyurl.com/25lhu52 2nd http://www.tinyurl.com/2c35ueg 3rd http://www.tinyurl.com/322yk89