Speaking of which, how will you be different from other small credit cards when it comes to merchant relations? If I go to "Jo Shmo's Taco Shop" am I still going to need a back up Visa card because that's all they are willing to take?

Probably not, my guess is that this will actually be a Visa card.

Most Visa and MC cards are branded as such but are actually backed by some other institution, like Bank of America or Chase.

Actually, ALL Visa and MasterCard cards are backed by some other institution. MasterCard and Visa are (well, were: it's more complicated lately) associations of banks.