mrman, I admire your tenacity - but I can't agree with you this time. Small clubs deserve their annual chance of A Shot at Glory and the Scottish FA should be wary of robbing the Scottish Cup of its essence.
The best I can do in terms of the format is a 7-round-plus-preliminary competition. The Premiership teams enter at the last 32 stage as usual, the Championship teams the round before, with League One and Two teams entering alongside the best non-league teams in the first round proper; it broadly keeps teams of a similar standard entering together.
Preliminary Round: 48 teams (9 Highland, 9 Lowland, 30 non-league qualifiers)
1st Round: 60 teams (24 Preliminary Round winners, 10 League One, 10 League Two, 8 Highland, 8 Lowland)
2nd Round: 40 teams (30 Round 1 winners, 10 Championship)
3rd Round: 32 teams (20 Round 2 winners, 12 Premiership)
4th round, and the rest, in the usual way.
Hope that adds up!