I think you're right.
I think what you say in bullet c. is also important. Supposing senators are supported by established parties and the war chest of a political party, which has Senate candidates running as well, has reached its limit, in terms of the election spending it is entitled to, because limits are proposed. Is it possible that, implicitly or explicitly, that party could ask potential donors to contribute to the Conservative or Liberal senators' election fund, since they are subject to the rules relating to individual donors, but have no spending limit and, therefore, are not required to abide by any objective limit? The reason I say Conservative or Liberal election funds is that the NDP and the Bloc are more in favour of abolishing the Senate, so that it would be fairly contradictory for them to be putting up Senate candidates. But we will see what happens with that in due time.