If I want to carry minimal cash, until I get to Mexico (at these 2 cities), what is the best way to deal with:

1) big ticket items, including hotel bills, restaurant bills etc - credit card?

2) small ticket items - where credit card is not accepted - US cash or traveller cheque, Canadian cash or traveller cheques, or using Mexico pesos

If using Mexican pesos, where can one get the best rate (and from what monetary instrument mentioned in point 2), at

i) hotel
ii) local bank
iii) airport (I know the answer to this one)
iv) cambios (is that what money exchange is called down there?)
v) ATM (using debit card)

PS-Do they take debit cards using the Maestro system (I have a B of M debit card)- obviously, Interac is a domestic Canadian system, only.