1: search
baby food (yes, this question has been asked already

)
2: a private van service will save your group money and time (it's less than the colectivo

) and we can provide a child car seat (the colectivos won't) Just fill out the form on the trip planning section for transport.
3: I don't know what transport MP offers. Hopefully they have shuttles.
4: Our daughter Elsa will be 9 months old on the 14th, lives here pretty happily, doesn't mind the heat (she gets alot of shade), likes the pool and strolling 5th. Have fun!