u/EnigmaClan

If in the US, the AAP parenting website (Healthychildren.org).

If you like social media, I'd recommend PedsDocTalk (Dr Mona Amin).

Just FYI, the flair you currently have is going to limit what people can suggest, since they need to link to "expert consensus."

Based on US recommendations, she could get the 6-month vaccines early, but not the MMR or flu shot. Those we don't give until 6 months on the dot.

https://publications.aap.org/redbook/resources/15585/AAP-Immunization-Schedule?autologincheck=redirected.

It would be reasonable to ask the instructor to keep the music at a lower volume if there are children in the room.

Generally fluoride supplements for children are given as one dose per day - usually 0.5 or 1ml. You aren't using it to flavor all her water, you're just giving a daily medication. We often flavor pediatric medications (Tylenol, ibuprofen, vitamin D supplements, vitamins, antibiotics, etc) so kids will accept them more readily.

At his age, he's got two forms of protection. One is the antibodies he got from mom, which are still present but waning, and the other is vaccines, where he's gotten one dose so far. Given that he's all up to date, I wouldn't worry too much about pertussis (whooping cough). Even if he did get it, it would be much less likely to be a severe case given the protection he has. I can't give you an exact number to tell you how protected he is, but I certainly would feel comfortable with you flying if I were your pediatrician.

Aquaphor/Vaseline are recommended by pediatric dermatologists. Not sure what your friend is talking about.

I disagree with your doctor. Weight loss in a child his age is never normal. Dropping percentiles can be, but not if it involves weight loss. Has he been checked for celiac?