I find none of these arguments convincing. You have the right to vote. Unless you're in Australia that means you can just not go vote also. That's your choice.

Voter turnout has an influence on the vote share the extremes of the political spectrum get. If you're on the extreme, you tend to go vote for your cause because you found your calling. So if enough people in the middle choose not to participate, you'll end up with difficult majorities and/or more extreme governments. The latter is also true if either extreme is convincing many of the people in the middle. And that's where tactical voting comes in. That's why I would personally lean towards a "go vote and vote for the best of the worst if nothing fits well" approach. But I wouldn't elevate this to the level of an 'electoral imperative' because it is a personal choice.