I wouldnt worry about nails. but would avoid hair dyes, and also bleech. I used to use Jolen bleech to light my hair on skin. but wen we start in ttc, i avoid that. are you taking any prenatal vitamins?? if no, its the best time to start taking.. any prenatal with folic acid is good .. Hope you will get your BFP soon. Good luck !!!
Nails should be ok, I would avoid the hair dye (most times it won't stick anyways because of the hormone changes), and the salicylic acid should be used in moderation. Everyone will react differently to different products. I would talk to your doctor and see what they suggest.
For me, I only have one cup of coffee a day to cut back on my caffenine intake. I also tried to get more sleep and to try and eat better.
I did avoid skin care products that had salicylic acid and I didn't dye my hair once I was into the 2ww. I would make sure I got a dye job as close to the start of af as I could if I needed it. When I was pg, I didn't get a dye job until I was out of my first trimester. You could always look into veggie dyes during that time.
As for nails, the fumes bothered me so again I avoided it during the 2ww.