and you'd probably want to take orbits/vectors into account, a djikstra-esque algorithm where the distances change is crazy.

Also, our signals are usually going very short distances very quickly and are very protected from solar/cosmic waves by the ionosphere. What kind of data loss could you get transmitting in open space across vast distances and time?

Interstellar space is pretty empty, and we have good models for it thanks to the radio astronomy community. Dispersion is low enough to be nearly negligible, even over tens of light years.

Determining theoretical interstellar link rates is a fairly straightforward link budgeting exercise, easier in fact than most terrestrial link calculations because you don't have multipath to worry about.