Will Neptune and Pluto ever collide, in the future, if their orbits cross..?

no. they really don't cross each other. the orbit of Pluto is not on the same plane as Neptune but they are million of miles away from each other.

They're soo far apart on their axis, for the 2 planets to collide, it would require intense magnetic or gravitational interference, and there are some people who believe that Pluto is merely a moon, if this is the case, Pluto could just be pulled into the orbit of Neptune as a satellite.

I think that even though pluo comes in closer to the sun their actual orbits don't intersect. Plutos orbit is tilted relative to the plane that the other planets orbit in. A good animation showing this can be found at http://www.astronomy.ohio-state.edu/~pogge/Ast161/Movies/SolSys.mov

Firstly Pluto has more than 1 moon 2 more were discovered in 2005 by the Hubble Space Telescope their names are, Quaoar and Xena and the combined gravity of these 2 moons and the moon most widely recognised Charon could cause Pluto to collide with Neptune when the Sun becomes a Red Giant and the gravitational pull of the sun and Pluto and Neptune might be enough for the 2 body's to collide. But we while never whiteness this because the Earth will no longer exist when the Sun becomes a Red Giant. I hope that this answers your question.

i'll make em collide if you want

Neptune and Pluto will never collide because Pluto's orbit is very tilted. I suppose if you projected far enough into the future there might be a time at which Pluto was both the same ditance from the sun and happened to be at the point where its inclined orbit crossed that of Neptune, but this is so vanishingly unlikely that the solar system would probably have ceased to exist long before.