Proportional representation creates more diverse parties. You don't vote for a "Left Democrat", you vote for a Green. Or a Pirate. Or some Tea Party equivalent. That's where you get "extreme" parties. But if you believe in the importance of free speech, you should also believe in putting a plurality of views into parliament (even ones you disagree with), where they can have a fair debate.
The fears over compulsory voting are ... interesting. I'd say that disinterested people make the best decisions, not party fanbois. Disinterested people are less informed, though. What's needed is some way of informing them at the poll booths. In Australia, party reps will hand out "how to vote" marketing brochures. This process could definitely be improved. Candidates could be forced to answer some structured questions, which could be written by an independent commission (to try to reduce bias, though the commission might be a little corrupt or biased). Stuff like "Do you support X, yes, no, or undecided".
The fears over compulsory voting are ... interesting. I'd say that disinterested people make the best decisions, not party fanbois. Disinterested people are less informed, though. What's needed is some way of informing them at the poll booths. In Australia, party reps will hand out "how to vote" marketing brochures. This process could definitely be improved. Candidates could be forced to answer some structured questions, which could be written by an independent commission (to try to reduce bias, though the commission might be a little corrupt or biased). Stuff like "Do you support X, yes, no, or undecided".