So after my red halfmoon jaws died in a horrible water change accident this past week

decided to go to a new petco and buy a new betta, was split between a couple of beautiful half moons and baby , decided to go with this yellow baby betta here and i have a couple of questions
1. do baby bettas need to be fed more often than adults?
2. should i do water changes more often? say every other day instead of twice a week? he will be kept in a one gallon unfiltered aqueon mini bow with a heater for the time bein
3. i purchased NLS betta food pellets since there smaller, but so far i put two pellets in and it seems uninterested, do i need to crush the food up in small pieces?
3. can you tell by the pics sex/fin type?