Re: future orbits?
It doesn't have _nearly_ enough mass to have a noticeable effect on us.
I write software for determining asteroid orbits from observations. _Usually_, the effects of asteroids perturbing asteroids are so small that they're lost in the noise. In some cases, if you're lucky and an asteroid is big enough, you see a noticeable perturbation on some other, usually smaller, asteroid... which is nice, because the amount of the perturbation can tell you the mass of the other (larger) asteroid.
For this to happen, you usually need the two rocks to go past each other fairly closely and slowly. There are a few hundred cases where we've been able to do this and get a reasonably decent measurement of asteroid mass. With the exception of a few spacecraft flybys (Galileo past Ida and Gaspra, for example), and a couple of tiny objects (couple meters across) where we could measure how much solar radiation pressure affected them, that's the source of everything we know about asteroid masses (and from that, asteroid density).
The rocks for which we've measured masses are usually dozens to hundreds of kilometers in diameter. For the bigger guys, the percentage errors can be quite small.