Um - I don't know how to gently break this to you, but no presidential candidate in recent history - and perhaps not so recent history - has ever had the power to do the things they promised when running for office. The closest was probably Ron Paul - and see how he ended up...
Sadly, the moderators don't ask questions about what a President is actually empowered to do either. They are hung up on the vast vision things that Congress has to deal with first. If that ever actually happened, then the questions might give some insight as to whether or not there would be a Presidential veto or signing of the bill, but otherwise it is just blather. If the candidates and moderators would stick to worrying about what Presidents can actually do, there would be a much faster electoral process and far fewer lies told.
If you get down to just what each candidate says that they actually are empowered to do, then all the candidates are back on the same footing - regardless of Republican, Democrat, or 3rd party affiliation.
What is their character and temperament? Do they show evidence of wisdom and maturity? Do they fear God or think they are God? Are they charitable and fair? How do they treat the poor and downtrodden? How do they treat those who are struggling? Do they want to ship them all off someplace where they will never be seen again? How do they handle their words and message? After all, communicating is a primary function of a president both nationally and internationally. How much baggage from their past are they going to be dragging into the White House that other governments can use against us?
Are they likely to lead us into a war nobody wants? Will they lead us into a war if needed? Will they negotiate treaties that help or hurt the majority of the American people or will the rich get richer and the poor poorer? Will our relations with other countries be better or worse in four years if they are president? How beholden are they to the existing government, military, and commercial entities? How beholden are they to the people providing the funds to get them elected?
Will they defend all the rights guaranteed to us by the Constitution and leave everything else not specified in the constitution to the states like the BOR says or will they let the latest "danger buzzword" chip away at a few more? Will they work to pull the country together or will they fracture it further? Since the President does control - to a point - the executive departments, these are real concerns. What will they choose to regulate if legislation fails? Will our freedoms, security, and privacy be better with this candidate in office?
Will they work with Congress or better yet, actually get Congress to work? Will government be bigger and more intrusive in four years with them in office or will it be smaller? Will our debt be bigger or smaller in four years with them in office? Most of these things come down to exercising their veto power over bad bills and budgets from Congress. A 3rd party candidate has a better shot at being willing to do that since they are unlikely to be beholden to their peers in the major parties.
To me, those are the things that matter in selecting a president.
There are a few swing states. If you live in a state where your vote really will make a difference, then by all means vote for a major party. If you are in a state that will go R or D without fail, then vote your conscience and pick who you think will be the best president, even if that is a 3rd party. We may not have true preferential voting, but in most states we effectively do. If you live in one of them, vote for the best person and feel good about yourself for a change. If you think that the R or D candidate is a good fit for the questions I have asked, by all means pick R or D. If you read those questions and consider the primary party candidates and blanch or retch, then choose a 3rd party. It probably won't make any difference, but you'll feel better for the next four years and it may help to provide ballot access and debate access in the future. At the state and local level, do the same thing. Vote in the primary that is likely to fill the most elected positions. Then vote for the best person in the election - regardless of party. Remember that Congress must be fixed before the President matters much and both main parties are responsible for its disfunctional state.