Great advice from HGrace.
I must declare myself not an expert in babies who join their families by adoption. My son was 3 when he joined us and my birth daughter is nearly 10.
To respond to your post:
"We spend lots of time on the floor playing, lots of hugging, kissing and letting him explore our faces and clamber on us."
- Excellent, that is what all babies need and I am sure he loves it and so do you.
"...he tends to fall asleep on our bed and then we transfer him to the cot when we are ready to go to sleep."
- My only though on this is it is generally better for babies to go to sleep in their own cot (or bed when older) rather than sleep elsewhere and be transfered because it can be harder later to establish a 'go to bed and go to sleep' routine.
I am not saying that you should not be with him etc etc, that is all good. I am not advocating letting him cry or anything in bed, just getting him used to going to bed and falling asleep there. My friend's child as a baby always fell asleep to the noise of the TV and now as a teenager still finds it hard to go to bed without the tablet iplayer whatever music or tv or something on!
"On the few occasions he really has not settled he has slept with us."
- We did co-sleeping and it worked very well but there are lots of safety rules, which should be observed, you may already be aware of them but in case not, please do check them out. You may or may not know your baby's birth weight, that can effect things. Lots of factors can effect co-sleeping so it is best to be aware.
www.nct.org.uk/parenting/co-sleeping-safely-your-baby
or
www.babycentre.co.uk/a558334/co-sleeping-and-safety
"The other day I realised he never gets upset or agitates for us to pick him up or feed him when out, the normal sort of stuff he would do at home. I also got to the shops the other day and realised his nappy had leaked and he had not once cried or got restless which he will do if he wakes with a full nappy. He has started babbling and smiling a bit more when out and is not unhappy per se, he just stares at people/thinks and seems a bit shell shocked. It struck me that he is either so absorbed by what is going on or is not comfortable expressing his needs when out- is that typical for a baby that age, I thought they would instinctively cry etc. at this age?"
- I am not an expert but I do think babies instinctively cry when wet, uncomfortable etc. Maybe there are some who do not. Certainly as children get older and get used to a feeling of being wet they may not notice it so much (e.g. older children who wet their pants a bit may get to the stage where it feels normal and they do not notice). I am not at all sure but she fact he does not respond to being wet would make me think that maybe when he was younger he was left in wet nappies to cry and not attended to and so has learnt that crying will not solve the problem of wet nappies. When babies first wee it is warm and maybe does not feel so bad, as it cools it feels uncomfortable (I would imagine) so I would imagine most babies would cry when wet or dirty BUT having said that it is sometimes possible to find a baby had done a pooey nappy not complained and got a sore botty just sitting in it! That happened to a friend's baby when I was looking after him and I felt terrible" So it could be normal or not. Maybe a chat to foster carers or find out about what happened when he was little.
Whatever the case you want him to complain when wet or dirty so you can deal with it. I do not know how you could address this except to be extra vigilant and change the nappy quickly when wet, when you can (it is not always easy to find a place to do it but when you can). If he does need to wait then (personally) i would make a big fuss of him and say things like "Oh poor babyBarbados, you are all wet. How horrible. That must be very uncomfotable/squelchy/wet/horrid (pick an adjective), Mummy is going to make it all nice and clean and dry. Next time you feel wet you tell Mummy." etc. WHETHER this will have the desired effect I do not know and other people who know more will hopefilly be along in a minute to say more!
I agree to stick with the quieter activities, quieter park times etc, the key thing is for him to know you and your hubby are the key points in his life and to not feel worried that anything scary might happen. I would also be talking to him all the time about where you are and what you are doing. Which you may aready be doing. He may not know what you are saying yet, but soon he will. EG 'So this is our local park, and it is nice and safe, Mummy is with you and will put you on the swing and stay close by." etc etc.
"He has been a little out of sorts this afternoon and I feel like we overwhelmed him this morning and am feeling awful."
-STOP feeling awful. It is not your job! You tried something you thought he might like and maybe he did and it tired him out or maybe he didn't like it. But either way you are learning all the time, tuning into his ways and moods so ... no negativity, please! You are doing a great job!
YES, IMHO it is a good sign in terms of progress that he seems happy and relaxed there with you guys.
For babies of his age lots of Peek a boo, reading stories, singing together, touchy songs like "Round and round the garden like a teddy bear" (if he is comfotable with it), swimming is good, close skin to skin, find a local baby and toddler swim, it will be quiter, the pool will be full of toys and floats and there may be a play leader who can lead songs etc. You could try a baby massage group, where you learn to do it, if it is offered. When ready it can also be good to try sing with baby groups when he is older. Whatever you like. Talk and express what you are doing and often adding in things about him, *Mummy's making some eggs and bacon, when you are bigger you can try it." If he jumps or responds to a scary stimulous, like the doorbell or thunder and lightening, you could say "Oh that was a loud bang, a bit scary, but you are safe here." etc
He is getting everything from you and your hubby to grow up knowing the world is a safe, nice, fun place and to have the language to express the times when he feels scared etc in a language to help him get the help he needs.
Sorry for massive ramble. Hope that helps. Congratulations.