OMG, reading this is giving me terrible flashbacks of planning my wedding last year and trying to keep everyone happy until the lady in my dress shop told me to f**k the lot of them, it was my day and I could arrange tables and photos and accomodation however I wanted!!!!
Like weddings, it's a very emotional time for you all, and you just get caught up in trying to keep everyone happy and stressing yourself out. If you decide that actually you would like to spend time with just yourself and DH and the new baby, then tell people exactly that, be honest. The ones worth caring about will understand. And it's not about everyone else, it's about you, your DH and your new baby!
My mum, dad and sister have already been told (no point beating around the bush) that should they come to visit, first on their list will be be doing laundry, making cups of tea and maybe even preparing meals, and letting me and DH adjust to our new roles in life. Luckily they live 30 mins away so if we really really need them, they'll (hopefully, but I would never assume automatically they'd drop everything) be able to come over. For everyone else, such as friends, we were going to set aside an afternoon at the weekend and invite them to come and visit. A friend of mine did that and it meant she knew when people were coming and could sit around in her dirty clothes and unwashed hair quite happily the rest of the time!
Now, despite all that bravado, we still haven't sorted out what to do with MIL who has invited herself and her hubby to stay for 2 weeks shortly after baby is due...better go and eat some more petit filous to psyche myself up for it!
Decide what it is you want, and stick to your guns, good luck!!