Nahum, If you are asking does the end justify the means, then I would say no!
I more or less agree with the rest of your observations. As I have moved around a bit, there have been times when whatever I vote was going to filter down to one of the major parties. However, first I believe in encouraging anyone who is prepared to put the time, effort and money into standing, and you are right, about needing 4 percent, or some such to get any benefit from the funding, but you might help them get their deposit back!
Then I live in hope that the scrutineers might, just might take some message back to the party when they see that I consider everyone, and anyone else as more worthy of my vote, than they are!