Maybe things have changed, but I became a landed immigrant in Canada without the necessity to renounce my US citizenship and paid no exit fees. For a time the US tried to tax my Canadian income, but Congress made it such that I would only be liable for tax on income that would have been taxed in the US but was not in Canada. I had no such income.
Umm, you better check on this again. I think things have really changed for someone in your position. Don't tell your Canadian bank you are still a US citizen until you find out exactly what your situation is.
Gosh, n00b - it must have given you the warm fuzzies that your Owners in CONgress were magnanimous enough to let a peasant like you keep some of the money that you earned for them...