"1. There were at least 8 parties for whom I'd never vote, would rank their ideologies equally poorly....

Think of the six or so major parties: Labor, Lib, National, Dem, Green, Family First, One Nation/Pauline

You can safely assume that any perties you rank after these ones are not going to get in. Unfortunately there is no fair way to legislate that people can do this without a high liklihood of people wasting their vote.

Also, if you see no difference between those parties, it is no cost to you if one wins over the other.