G S,
It is such a hard place to be in, being a first time mom. You really sound like you have your head on straight, and are gathering lots of professional advice to make the right choices for your daughter. The fact is, one method is not right for each family and for each child.
Here's what I do, and I don't necessarily recommend it, since I am a bit passive/aggressive, it's just my way...
When I get advice from somebody on how I do something different from them, I come back with 'isn't it amazing how babies are different and while one thing works for one, it doesn't for another?' - or if they comment on something they are doing (i.e., discipline area works best for this comment) I say 'really???? how's that working for you?'.
On the other hand, keeping your mouth shut is always an option if you can't find a tactful way to nip it in the bud. When i find myself in that place, I will call a good friend and just vent :) I know it's not a very christian way to behave to bicker about somebody behind their back, but I really try to follow the rule of 'don't say anything about somebody you can't say to their face'.
Some people have very strong feelings on certain parenting issues, I find this especially true when it comes to breastfeeding/formula. I had a friend who made it sound like I was poisoning my kid because i was formula feeding (nevermind the medication I was taking for post partum depression (darn near psychosis for me...)passes into breastmilk and is unsafe). I too use a 'generic' brand - the fact is, the FDA regulates the manufacture of baby formulas - they must all be made to a minimum level of nutritional quality. I don't think it's safe to drink unpasteurized milk, but people who live close to the source, do it... to each their own ;-)
Anyway, I think you're doing the best you can... arming yourself with lots of information, making informed choices... it certainly can be tiring dealing with those who are a bit more ignorant on certain subjects when you've worked hard to do your research. I am not saying 'ignorant' in a deragatory way - people mean well, and I try to assume positive intent when people give unsolicited advice...
Plus, I dont like to hear it when people pull this card on me,... but, your hormones are still playing a role in your body. I know that I have never been the same... it seems once you become a parent, your whole mentality changes :) we're not born the strong 'mama bear' that could walk thru flames to save your child in a fire... EVERYTHING changes :)
Good luck to you, and rest assured that you're doing just fine... even if you don't know what to do in a certain situation... sometimes it's more important to know what NOT to do :)
Congrats on your new daughter - God Bless