Hi!
Congrats on new baby :)
About the bumps - if they're small and "beefy" then it's probably a yeast rash as opposed to a diaper rash. Yeast rash (infection) needs to be treated differently than a diaper rash. You'll know it's yeast if it spreads quickly, and moves on to his stomach, and upper thigh area. Also do a google search for "infant yeast infection pictures" , there are a lot of pictures of it on the web, it'll help you to identify it easier. Because you mentioned it on his upper thighs - it's probably yeast. Or - depending on what he was wearing yesterday, it could be a simple heat rash. If it's a heat rash, it'll go away almost as quickly as it showed up.
With the formula, you should introduce it gradually, you can start w/ a ratio of 1/3, then 1/2, then 3/4. Although, we have done complete transitions (meaning full replacement) w/ many formulas when we realized our children were allergic to a paticular kind.
The dandruff is called cradle cap, and it's very common in babies and toddlers. All 4 of mine had it. We tried everything!!! We've tried baby oil, olive oil, lotion, special shampoos, etc. The only thing I've found that worked well is a shampoo we found at Whole Foods (and Sprouts if you're near Plano) called California Baby - that stuff was a life saver! It's pricey - it's about $9 a bottle, but they have such little hair that it'll be a while b/4 you go through the whole bottle. My 3rd child had it the worst, until he was about 3 years old - that's when we discovered the California Baby and it finally made it go away. We used it for him and his younger brother (who was about 1 at the time) and it cleared both of them right up! My older 2 had to deal w/ all the weird lotions and oils, lol, but they did eventually grow out of it!
I'm very sorry to hear about your mom passing! It must be very hard for you to not have her with you while you are learning to become a mother yourself.
If you are near Garland, I have a great dr on Saturn and Northwest Hwy who see's all 4 of my kids. He is awesome and has been the 1st person to identify some of their issues. I'm very picky (we've been through about 10 pedi's in the past 10 years), and Dr Parker (who is actually a family practicioner) is the only person I feel comfortable taking my kids to. He sees our whole family actually. His staff is wonderful, my kids just adore him and his nurse!
Hugs and Prayers to you!
--S.