Run if you enjoy running/training/competing, don't run if you don't. Whether you "make an impact" on the team will, in the long term, likely mean less to you than the experience of being on the team. Like the previous poster said, it's very possible to run three seasons and do well academically - I did. If anything I think the structure of regularly-scheduled practices helped me manage my time better.
If you're on the fence about it, I'd say give it a go. Take a "summer of Malmo" this summer - give it an honest effort but don't stress. In hindsight I put more pressure on myself than I needed to, especially my freshman year. Once you're done with HS running leave that all in the past - forget your old PRs, forget your old weekly mileage, and start fresh. If you hate college running after a year nobody's going to force you to continue, but if you enjoy the sport, give yourself the chance to make some breakthroughs and have a good college running experience.