I would dig a little deeper into the 3.5 GPA requirement. For instance, is this by semester, year or overall GPA? Can you reapply for the scholarship if you fall below a 3.5, and if so, how quickly? If it’s by the semester it means one difficult class could result in the loss of your scholarship. A C in organic chemistry would mean that anything less than straight A’s in your other courses could mean you’d be spending the next semester or year paying full tuition.
If there’s a grace period (e.g., you have a semester to get your GPA back up) or the average GPA for those departments is north of a 3.5 I’d be less concerned.
Is the $4000 parent and $4000 student directly paid to Bates? Or is some of that to pay books and personal expenses? (Presumably all of the $1700 work study would go to books and personal expenses.)
If the direct cost that has to be paid to Bates (not including loan) is something like $7500 (or all $8000), that could be difficult if your family’s income is lower middle class. Maybe you have some savings for part of it, but coming up with $4000 yourself and working $1700 work study might not be easy. And are your parents fine with paying $4000 every year to Bates?
On the other hand, if you’re borrowing just $2000, you could borrow up to $3500 more to lower that direct payment. You could be able to save $2000 at most over the summer, with $1000 going to expenses for the year and the other $1000 directly to Bates. (I don’t think you can really be sure of doing more.) So you may be able to get the amount to pay down to a level you and your parents are comfortable with.
If Bates means working hard in the summers, borrowing at least $10K and maybe $20K, and having your parent pay several hundred a month, maybe it’s worth it. I think your parents’ opinion is a pretty important factor here.