Just to add our story (although not to say it is right you and your family!)
At about one yr old, we moved dd onto an adult single mattress on the floor, pushed right up against my side of the bed (duvets on the floor on the other side for the first wk or so but actually she never rolled out!) She was about 10cm lower than me (our bed is quite low) and was an early walker so was able to wake up and climb into our bed between us when she needed to.
We got her own room ready a couple months later and put all her toys in and another mattress on the floor and that was her playroom (should also point out that we live in a flat which has one big 'everything' room and the bedrooms coming off that in a row, so she could easily play in her room when I was cooking or something and we could still see each other and 'chat').
At about 18 months, we started putting her to bed in her own room (can't remember if she indicated that she wanted to, or if we just thought to give it a try and it worked). We leave both bedroom doors open at night and she just wanders in if she needs to in the night (rooms next to each other, and we have a nightlight in each room). Sometimes she sleeps the whole night in her bed, other times she comes in middle of the night (say 1 or 2 or 3), other times she comes in at 6 or 7 and will often then sleep an extra hour or so - it varies.
For the night feeding, at about a year I was only bf her when she woke at night (she just started drinking more from a cup and the bf reduced accordingly) and at about 15 months (? - shockingly bad memory I have ) she suddenly stopped waking at night for a feed and that was that. But I'd be inclined to put that down to her and the way she is rather than any parenting or techniques on my part.
For the record, ds was born earlier this year and we are co-sleeping with him. Dd still likes to come into our bed now and then (we have a swapped our bed with our guest bed which is actually a double futon and then have the spare single mattress next to it, so it's like triple bed - am tempted to keep this even after the children have left home as the space is lovely!) so it now goes, from left to right, wall, ds, me (on double futon) dd (optional extra ) dh on single mattress - dd will either snuggle up to me or dh.
This seems to work for us so far.