My only concern with being in school while attempted to get started in REI is because of the fact that it will be hard to get loans due to not having a current income, plus id feel more secure if I had extra income to cover any additional fees/emergency expenses!

This has been really useful for "C" properties where tenants sometimes struggle to get work hours during slow seasons; I have found that tenants tend to "save" their late allowances for actual emergencies.

The reason first started with educational purposes but now I see myself emerging myself in the industry entirely. 

You also do not have any cash leftover for emergencies.

How do they handle maintenance complaints or emergencies from tenants?

I don't want to mess around with borrowing against my primary house, unless I had to for emergency.

The Internal Revenue Service has provided temporary relief from certain requirements of the Internal Revenue Code to allow owners and operators of low-income housing projects located anywhere in the United States and its possessions to provide temporary emergency housing to individuals who are displaced by a major disaster from their principal residences, regardless of income.https://www.irs.gov/newsroom/low-income-housing-un...

When starting out with a house hack, how does one ensure that the property is managed and emergencies can be dealt with while they're away for a day, up to a week? 

With education, time, and taking consistent action in any endeavor, clarity emerges. 

Secure the house, notify emergency contacts and develop a plan.