I hate to debunk the professionals but cereal in the bottle is not an old wives tale-- unless Im an old wife.
My first child slept through the night at 4 weeks. I breast fed all day but the 2am feeding was formula. I always wanted my kids to be use to formula in case I needed to leave them for awhile and didnt have milk stored.
At 3 months he decided to stop taking the bottle. He started waking up at night. When it became a twice a night thing I started putting cereal in bottle with breast milk and guess what----yep he started sleeping through the night again.
He even took the formula back, which was good because of health issues I had to stop breastfeeding soon after.
My second son slept through the night at 5 weeks. I dont recall when I started him on cereal but I do remember never going through the regression of him waking at night again.
--fyi- when I say sleeping through the night, their last bottle would be between 10-11pm so it wasnt like I was putting them down at 8 and them sleeping til 8. It was more 10-6 or 11-7. Still very good for 4 and 5 weeks!
I didnt start either child on other solids til 6 months.
My oldest son is a healthy 20 yr old who is in prime athletic shape. My second son is a very healthy tall slender 18 yr old.
I was never one for pushing a certain eating style on them. I never made them clean their plate or eat stuff they didnt like. The only rule we had was that you had to at least try it. They never minded trying new things because they knew they would not have to eat it if they didnt like it.
I found later that this made them great dinner guests at their friends homes because they were open to trying whatever was put in front of them and as I discovered when I would make something new they had already tried it and liked it.
I seriously let my kids eat chicken nuggets, fish sticks, pbj, til I thought they would turn into them. Maybe not the best example but it worked for us.
Good Luck!