To your points:

- Without money, do you have a voice?
        Yes.  At the ballot box.

- Taxpayers already pay for three-quarters of a political donation, and almost all those donations come to well-heeled donors who don't need the subsidy.
        So get rid of it.

- With all the tax credits, the current system of super-deductions is likely as costly.
         So get rid of it.

- It eliminates cash for access.
         No it doesn't and you know it.

- It eliminates the discrepancies in our tax receipt structure where any donation to the Fraser Institute is fully deductible (...), yet a donation to the Broadbent Institute is not. Why is that?
         That's the organisation's problem.  Go complain to them.

- Political parties can get on with policy and analysis, not worrying about fundraising.
         Life's hard.  Suck it up, sunshine.

- Set a minimum threshold for support, say 1 or 2% overall of the overall vote.
          Stop picking my pocket to support an oligarchy.