Like others, when I do I keep it to myself and DP.
I have friends who had kids after me and wanted to know what my inspirations were cos they want to do things the way I do with DS. That means that it's obvious I'm doing something 'different'. This also means that the friends who have babies who then succumb to the baby training and non-tactile parenting are determined not to want to do it, and it's not because I haven't spoken up about it. In other words, there are some people who have already made up their minds and there isn't much you can do - like people who insist that formula is as good as breastfeeding, when that is factually incorrect, and they know you're still BFing. There's just no point bringing it up. Same with attachment parenting - I just 'do' and 'show' rather than advise, unless asked. I also will talk about attachment parenting concepts and practices in conversation, as if they're a normal part of life (in a 'well, you know, of course' sort of tone, so that it doesn't look like I'm emabarrassed to bring it up!), so that if they decide to take any of it up, they will know that at least one other friend does it, too!
As for an abuser living in the house, an anonymous tip off is the order of the day here. There's a small child in that house. Also the smoking in the house - there HAS to be some kind of wellbeing issue there! I think the both are serious issues.
There are times I've stepped in for the wellbeing of a child, over the wellbeing of the friendship and come off worse for it once. Father has some pride issues (or something) and I've been outcast ever since - the child was about to be totally demoralised and punished for something that had already been dealt with before the dad came home, on top of the way the child had been treated a month or two earlier on a weekend away with us all, and on various camping trips. I'd had enough and the child's mother is a doormat with these things - my DP knows that if he steps over the line, I'll have to break ranks with him and side with DS because DS's emotional safety comes first for me.
Also, I had read articles and chapters in books about standing up for children when their parents are eroding them (great chapter in The Natural Child, available in libraries and through ABA's Mothers Direct). That influenced me in this specific case where I made my call. Kids are not chattels, and some parents believe they are and will take exception to implied criticism of their 'disciplinarian' ways.
Anyway, in other respects, as sad as it is to know of a child who is parenting using books called Save Our Sleep and Contented Little Baby, there isn't much we can do except be shining beacons of example. Particularly when you know, through experience and contrasting with non-gentle examples, that gentle parenting achieves the more satisfying relationship in terms of long-term objectives for parent and child (who will one day be an adult - often forgotten!!).
It's your call about the bf and smoking, and I know that's one aspect I wouldn't budge from - I'd be vocal about the smoking and proactive about the bf. Your gut feeling is yelling at you!