I slept exactly the same as Hestia when DD was tiny. But I was still nervous, and so was DH, so he actually sat up next to me keeping watch the whole time I slept. I was just at a point where I couldn't sit up anymore so we chose co-sleeping. Once we got used to it and I realised I woke at the tiniest thing, we got more comfortable. I just made sure she had space and there was nothing but mattress anywhere near her. When she got bigger and was moving more and I was more comfortable with it, we made sure there was a barrier on her side of the bed, I gave DH most of the quilt and only took enough to cover me to the waist and none could reach DD.

As for swaddling, I've also read they shouldn't be if co-sleeping. DD never liked it so we stopped that pretty early, but I guess it's because if he does need to move or something, you're less likely to notice it and wake if he's swaddled?

With gas, I went with the whole "breastfed babies don't get gas" which was such a joke for DD, she could fart all night lol. I didn't burp her if I fed lying down, because even if I was sitting up and burping her it didn't seem to do anything. So if she got grunty, I'd lift her legs and push her knees to her belly to help it down, and massage her belly in little circles. I kind of just automatically did it in my sleep.