My oldest (bio) nursed until he was 4y 8m, and it was
a stretch to find new ways to comfort a non-nursed child. It was very easy to just pop in a nipple whenever my oldest fell or was upset or whatever. But comforting without nursing was something we learned to do, just as I learned to comfort my oldest by nursing IFYWIM. Bottle-nursing is, IMO, creating the effect of nursing as much as possible while bottlefeeding. For us, this meant holding him in a nursing position, holding the bottle for him (if he reached for it, we had him hold our hand or fingers instead) as I think that an important part of the nursing experience is that the baby depends on you to provide nourishment for him instead of him providing it for himself, not letting them walk around with a bottle--I think that the enforced periods of calm that nursing provides are important as well, only one person providing the bottle (usually Mom), and allowing self weaning from a bottle and/or pacifier with extra tooth care to prevent cavities from formula. All of this has the caveat, of course, of following your babies cues. If they are used to having it done a certain way, such as holding their own bottle, you have to go slow in making any changes. Also, it can be too intimate an experience for some babies right away, and you need to be respectful of that as well. They need to get to know you, so you can't force yourself--there is a balancing act between encouraging attachment and forcing youself on them. I thnk it is kind of like early dating--you need to let them know you are interested without coming on too strong
Regarding cosleeping--it is actually often encouraged by the agencies to cosleep in international adoptions! In many other countries it is the norm, and the babies either sleep with a foster mother or with other babies, so I wouldn't worry too much about that one. In our case, our youngest did cosleep with his FM, and we coslept for the first month, but he really preferred his crib, so we followed his lead and let him sleep there. I think that because they slept on the floor, he had a lot more room than squished into bed with us, as his paperwork noted that he rolled around a lot in his sleep
so none of us coslept well together. But especially that first couple of weeks, and naps where just one of us laid down with him so there was more room, it was a really good way to connect. We also did skin to skin contact to foster bonding, and I also was able to nurse him for 2 weeks, but unfortunately new teeth and a new nursing relationship don't go well together and we had to stop. But those 2 weeks made a big difference in our relationship. Sometimes he will still come up to me, 1 1/2 years later, and pat my breasts or lift my shirt and mouth me just like a bf toddler, so I know it had an impression on him. I also suspect that he was dry comfort nursed by his FM for a variety of reasons. IF you have any questions, feel free to ask me. Like you, I did wonder at the beginning of our adoption journey how I was going to parent with my biggest tool missing from my parenting toolbox. But you learn, and you adapt, and you become a better parent for it.