Three paragraphs below correspond to your three sections 🙂:
My understanding is that the joint income won't affect us married people for vet school because we aren't eligible for need based loans (at least for federal/private loans). I got my loan package offer for UGA already and even though my EFC with both of our incomes was more than school costs (in-state) I was still offered the full loan amount to cover tuition/fees and cost of living.
I'm curious to see how this will go for us, but we are planning on paying for everything on my spouse's salary. It's going to be tight - especially because we will be living in different cities while I go to school, so we will be supporting two households on one salary when we are used to living in one household on two salaries. We're pretty frugal, so we think we can do it and we have done the budgeting and math and think it will work. If we can't though, I plan to take out as few loans as possible to make up the difference. As long as nothing changes, we would at maximum take out loans for tuition while covering cost of living with my spouse's salary. Interest on loans is a real bummer, we're just trying to avoid additional debt as much as possible. Re: parents...everyone is different, but I would not ask my mom to contribute even though she is financially capable (my dad is not an option, we are estranged). On the flip side, my step-sister just graduated medical school and she is married, but they were not in a position to pay for school or cost of living with his salary/stipend. She borrowed the money from her uncle as a "loan" with .5% interest starting 6 months after she graduated. It was a good option for her to get significant help from family while still feeling ownership over her finances.
I can't speak to paying back loans for vet school yet since I start in the fall, but I did take a small amount of loans out for grad school which we paid off as a couple. We combined our finances, so it's hard to say exactly whose money went where if that makes sense, but we just paid the loans off as quickly as possible with joint money. At the risk of oversimplifying it, we pay our bills, etc, put a set amount of money into a retirement account and savings, a little money for fun/travel, and then the rest of the money went to the loans until they were gone. We saw it as an investment in our future together to be free of the debt and to pay them off as quickly as possible to minimize money lost to interest - but again, some people view debt brought into the relationship differently and there's no wrong answer, it's just what you're comfortable with as a couple 🙂.