Common tasks include guiding (for example, blind, severe physical disability), alerting (severe diabetes, seizures), retrieving/operating (pushing buttons, switches, etc).

Insurance is expensive, there is a lot of extra maintenance like painting or electric in common areas that don't apply as much with smaller units. 

Where I live mice are common as the cold weather drives them inside.

Everything you said is common knowledge.

This is a common misconception but we're an online platform where the owner chooses their own price and selects their own tenants.

I’ve heard that this neighborhood doesn’t really have any problems from a social worker but outside areas aren’t good. 3/4 units are currently rented at $900 each, renters pay utilities.

Alternatively, once you have a full time job (or an employment contract), you should be able to qualify for a loan and utilize a Down Payment Assistance program.

The most common is leaning on your agent for their expert advice.

But usually for a tenant occupied it's like $90-120 per monthI've noticed a lot of multi-family buildings are pre-WWII housing inventory - are there restrictions or issues common with that (historic districts, crazy high utility costs, etc)?

Your question is a very common question, and I can appreciate your concern here.