My tips are

(1) If you know people aren't going to be supportive, don't bother discussing it with them unless they ask. I had a similar experience with our home birth plans. People said things like "oh, that's interesting/nice" but you could just see them thinking "she has no idea, once she realises what labour is like she'll want an epi". Same with co-sleeping. We co-sleep or not, depending on how we're feeling, how baby's feeling and what we want to do at that particular time. But mention it to some people and they act as though we have signed up for some dangerous cult!

(2) Don't commit yourself to anything! You have the right to make your own decisions, but you also have the right to change your mind later. I was quite adamant that I would only use cloth nappies. Then I got sick and depressed, baby had reflux, couldn't breastfeed, wouldn't sleep and had about 10 pooey nappies a day. OK so it only took an extra 1/2 hour a day or less do deal with the nappies, but I couldn't spare that time, so we quickly changed to disposables. With #2, everything was so much easier so I have gone back to using mostly washable nappies for both kids during the day, with disposables for night-time and any other time I feel like it.

I wouldn't worry if someone gives you disposables. They may come in handy if you're unlucky enough to all get a gastro bug at once or something like that. And if you don't use them you can always donate them to someone else who will.