Loan - Go residential if you can. As mentioned, there are limitations but if you can get residential, do it. You'll save $$. (lower rates, longer terms, higher LTV ratio's)
Terms - I recommend you get as long as a amortization as you can. It gives you flexibility. You can always pay on it like a 15 year loan even if it's a 30 year. But if something comes up and you are at 15 year, you don't want to skip a payment.
Look at local banks, shop around. Hopefully you'll find a good match and then develop that relationship. Tell them you want to grow. It works.
Lease - do an annual lease. Most campus this is the norm.
Big Complex competition - yes, you're competing for the same pool of students but complexes don't have what a house has. For example, a yard to have parties, grill, or do whatever,4-6 roommates (fraternity or sorority love this), no one above or below you, etc. Think like a college kid. Houses have the "cool" factor that complexes sometimes can't replicate.
taxes - if it's a rental right now, taxes shouldn't double because nothing changed. If you do renovations or pay a ton of money, that could trigger higher taxes. Not sure the government knows how you're using the property.
Tenants - be careful, I wouldn't go there (GPA, etc). But you can be selective. Ask for references, specifically last land lord. CALL THEM. Use your gut. Almost as equally important, be an active landlord. Be clear on your rules and expectations but then be around often. It's the out of state or ones managed by a company that go to crap fast. Kids will be kids, you just have to be active with your management.
Final advice - START SMALL. You're going to make mistakes and learn. I'd rather those mistakes be small at first.
