Hi Cords, sorry I haven't replied again until now. My DS was just 2 and a bit months. The advice to try tummy settling came from my mum after she thought he prefers his tummy as the only place he would nap for a long time was on my chest.
Just thought of the reason why we changed back to back settling, don't want to scare you but thought it best to mention than not so you can look out for this - DS got in the habbit of sleeping on his tummy with both hands up so he could rest his forehead on them. This then meant his mouth was straight down into the mattress. He could still get air in at the sides but I started to notice that I couldn't hear him on the monitor as clearly and every time I went to check I'd find him in that position, rather than head to the side which he'd being doing for months.
One of the SIDS possibilities is when the baby breathes in too much carbon dioxide, usually when face is down or covered by their arms. He started doing this almost every nap, so that's why I reverted to back sleeping at 4months. He still grizzles (and more!) when I put him down on his back and so far the sleeping bag is stopping him from going over to his tummy again. I will probaly let him sleep on either side once he can roll back both ways.
So a compromise was on tummy at 7pm and then at next waking onto back for rest of the night. Must admit this was after a feed so he was very grogy when going back.
As for the bath problem, we found a few new bath toys did the trick. He gets excited every time now as he gets to play with the "special" toys which only come out at this time. Also agree about a flanel on the tummy, keeps them warm and snug. Also found to put them in slowly, toes first and then up to bottom before laying them back so they could adjust to the temp and feeling.
As for nappy leaking - fraid I can't help with that one as we too get the same problem!
Apologies for the v. v. v. long post!