There are many users who ask questions that are unrealistically answerable. Should any educated answer be given to get it answered or maybe encourage a more correct answer? Unanswered percentages seem to matter, but why? If the question is impossible to answer should they be left unanswered?
Regarding your title question, the answer is no.
Up votes are for good posts, and you have extensive guidance on what makes a good post, both in the help pages, the faq, and from many individuals across Stack Exchange who have talked to you about this.
We absolutely do not want you to upvote everything regardless of quality - your profile suggests you think it is good to upvote everything, but the opposite is true: it ruins our ability to distinguish good from bad.
If you think a question is unanswerable, don't answer it. If someone else writes a post that is a good answer for the question, upvote it. If someone writes a post that seems like effort is put in, but it doesn't answer the question, down vote it or flag as Not an Answer.