Curious to see what others think

💙Mia • Cajun & Proud, Conservative, wife to Royce 4.12.14 ❤️, mother to Bennett 8.12.15 💙
When it comes to voting (for president in be U.S.). I am a firm believe that when voting you should do research on all candidates, and vote for who you agree with the most. By that I mean, agree with their politics the most. We all know all politicians lie, but you can only do so much with what you're given. I believe it is wrong to vote for someone based on: 
Their sex
Their race
Who they were or weren't married to
Who they are related to that previously ran or was in office 
Their political party
With that being said, MOST people only vote republican or democrat, although there are several other political parties. Given the fact that MOST people only vote for republican or democrat, do you feel voting for any other political party is pointless? 
Let me phrase this in a way that isn't offending: I do not mean that your opinion or choice is invalid or pointless. But given that the chances of someone other than republican or democrat winning the election are slim, voting for one that isn't these two, will not "hurt" or "help" the one of the two you dislike or like more. 
For example, if you vote independent because you don't really care for either republican or democrat, but you dislike the democratic candidate more than the republican candidate, your vote isn't being heard. Your independent candidate isn't likely to win, and the "lesser of the two evils" between republican and democrat (in this scenario, republican) isn't getting your vote, but your "against vote" isn't going to the candidate that can likely beat the other option (in this scenario, democrat). 
So, what are your opinions on this topic?