Yes, definitely agree with much of what redhen and slimbo say above...sorry if this is a bit long, will try not to bang on...
"DPs children are very spoilt, he and his ex had a lot of money when they were together, and now he doesnt, but both him a skids cant really accept they are actually quite poor."
So true here! My DH also finds it hard to come to terms with his/our financial reality; they used to have more money...DH had a settlement from his first wife's death, which he spent rather quickly giving playing DisneyDad - so now there is no money but the kids are used to getting 'the best'. We have lots of conflict over money, because of this and because I don't believe anyway that kids should have (even if we could afford it which we can't) some of the things they'd like.
"You seem to find, as the woman, whether you want to or not, you somehow end up as primary carer."
And this is very true. In our house, we have a jobs rota, and also DH is very much a 'new man' and does quite a bit...but I still somehow manage to see more that needs doing than he does. We share dinners and washing up, but everything else falls to me first (if I ask DH for help he always does, but it doesn't occur to him). I do all the laundry. I also end up doing all the long-term planning and worrying for all the kids, and because DH is crap at keeping track of things, it is me that has to remember appointments, the names of the kids' friends,what they need to take to school...I am the primary caregiver for DD, just as when I was a single mum (which tbh is how I want it), but have also fallen into much of the parenting of the older kids. So now I feel like I am looking after a household of five, whereas when DD and I lived alone, everything was so much easier and I had so much more time to myself.
I also had more time with DH when we did not live together! Slimbo is right - much less effort is made to romance or 'date' me now that I'm in the same house. I know this would be true even without the kids (you certainly hear it from even childless married or cohabitating couples), but the SCs make for a really extreme situation! If you DO eventually decide to move in with your DP, you must plan for this and have real dates and also real time together without the kids, in the home. It's critical.
The bedrooms...yep. Just recently had a monster argument with DH (posted about it here so sorry again if repeating self). DSD is talking about taking a year off before university and staying at home. When we moved in here, it was stated that DSD would have the large bedroom until she left school, and the we'd move the other kids 'up', so that DD (just a toddler now) would have a decent sized room instead of the tiny box room she's in now. DH was astonished when I said that we were sticking to this - if DSD stays at home for a year, it will be in the tiny room. I was astonished that he just assumed DSD would keep the best room in the house and didn't even discuss any of it with me.
So even though I feel that moving in together was the right thing for us as a family, I don't always feel like it was a great deal for me. As I said above - I'd do it again, because the alternatives for us were not workable, and I am optimistic about it now because things are moving so much in the right direction. But it has never been easy and I have struggled with feelings of depression and loneliness...and resentment. I've had times of just longing for my single parent days! I knew it would be tough, and it has been.