From wikipedia;
> Space probes have yet to reach the area of the Oort cloud. Voyager 1, the fastest[60] and farthest[61][62] of the interplanetary space probes currently leaving the Solar System, will reach the Oort cloud in about 300 years[6][63] and would take about 30,000 years to pass through it.
Space is vast; matter is (relatively) sparse. Moreover, matter tends to clump together, concentrating what little there is.
Either way, I wouldn't be too worried about collisions. To emphasize again, Space is really big and really empty in the grand scheme of things. Outside of a star's gravitation pull, we'd have to be extremely unlucky to have a collision once we get past the planets. And AFAIK there's no signifigant exoplanet within the Oort Cloud.
As for stars: for reference, The Alpha Centauri is the closest to us and that is over twice as far as the edge of the Oort Cloud. It's not like we'd be able to get any data by that point in time, But I imagine crashing into another star outside of our Sun would be a celebrated moment rather than a somber one.
1: https://en.wikipedia.org/wiki/Interstellar_travel#Wait_calcu...
> Leia: Chewie, get up here! We're going into an asteroid field! > Han: That's no problem. Just don't hit whatever asteroid might be within a hundred thousand kilometres. > Han: They're in nice stable orbits too, so it's easy to avoid them. > Leia: Okay, fine. We're going into a massive region of randomly moving, closely packed, enormous giant space rocks. > Han: Gaaaaaah!
The same way the Saturn probes went right through the rings and didn't hit anything.
Even if it looks like a "cloud" or "ring", that doesn't mean that it is "dense". There are whopping distances between objects in space.
It is way, way, way more difficult to actually "hit" something in space than it is to avoid something.
I would think if they were close they would just clump together under gravity.