First of all, it's very clear that Rand's public pro-Israel stance is to insulate himself from claims that he's anti-Israel or even antisemitic. His outreach to minority voters is an attempt to do the same thing with the inevitable smears of racism that are going to come down the barrel in very short order. Does anyone really believe he can get the black vote? Does anyone think he thinks he can? Of course not; politics is a game of chess, and Rand is quite a good chess player. But I digress.
Lets say Rand is a complete sellout when it comes to foreign policy, just for argument's sake. Hypothetically postulate that a Rand presidency maintains the warfare state status quo. Postulate too that he cuts spending, taxes, pushes drug war reform, results in a better fed chairman and better monetary policy, welfare reform and perhaps even a move toward a negative income tax (not a position Rand has espoused AFAIK, but he should), immigration reform or non-corporatist market deregulation. If all or even any of the above happens, a huge amount has been accomplished.
Think of the alternative: yet another Bush or Clinton presidency that not only maintains neoconservative foreign policy, but in all likelihood doubles down on it and absolutely none of the benefits listed above. Democracy is a truly shitty system, that inevitably leads to pandering to plebeians and choosing the lesser evil. I wish we didn't have to do that, but we do, and it is a petulant, counter-productive move to to just take your ball and go home if you have an imperfect candidate that plays ball on the world stage.
So many libertarians seem to have no real desire to actually change the country and lead it in a better direction. They're perfectly happy to pat themselves on the back for their "principles", take potshots at the establishment all the while crowing about how they're "above politics" and that they've "seen through left and right". Well, congratulations boyo, your principled stance has rendered you a political irrelevancy, a curiosity at best. I actually want to see a more libertarian country in my lifetime. If you're too "principled" to support the only guy who's remotely capable of doing that because he disagrees with you on a few issues, then you're part of the problem. Abandoning libertarian principles will do nothing to move the country in the right direction, but so to will sticking to those principles to the point of being a political nonentity.