Bruce,
A large transaction fee penalises registrars with many names.
Every registrar paying the same fee would be fair too and would meet your criteria no.1. It would however make it difficult for small registrars.
The key is to find a reasonable balance between the two extremes.
At issue is the fact that ICANN as the "technical administrator" will soon need to review all registrars financial to determine who falls on which side of the balance point. ICANN currently has no facility for the tax payers to challenge their determination, if you happen to disagree with ICANN their assessment. Furthermore, learning today that the budget was circulated among the top 10 registrars certinaly does not create an aura of an "open and transparent" budget process. This whole budgets gets ICANN one step closer to becoming an international Tax Assessor and Tax Collector. this isn't what the green paper advocated. -rick