Credit Cards and Banks Question

[Muslimah]

Salaam Alaykum:

1) I am interested in attending this Saturday's Cavalcade of Lights; however the sponsor is Scotia Bank, the same sponsor for Nuit Blanche in Toronto and the GTA Eid celebration. The primary profit of conventional banks come from interest/usury, a profit that is forbidden and unjust in Islam. Now, would it be permissible to accept donations from banks? Would it be permissible to attend events sponsored by banks? Would it be permissible to earn a salary from banks?

2) RBC has an "No limit Banking" for students and non-students. The fee is waived, if the person has a credit card. The primary profit comes from interest/usury. Now, insha Allah, I hope our communities will have halal alternatives to the conventional credit cards that have interest for those who do not pay within the interest-free time. My question is for the rewards credit cards or the credit cards that benefit. For these credit cards to benefit, they may have agreements with other parties or companies. This may mean that the banks use their interest-based profit for these agreements. With this possibility, would it be fine to take advantage of these credit cards with benefits?

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Best wishes,

Afifa Darabuddin