It's only a stepping stone to break free.While you are slaving, eat ramen, roommate up or live in trailer, avoid Starbucks and tuck every dollar you can squeeze out into a bank account. need 20% down and money for materials. so for 80K home (trashed), you will want 35K banked to get started, just a rough idea.Then, get pre-approved.

In terms of house hacking, I would suggest also looking for housemates/roommates perhaps on Facebook for groups there who are looking for rooms.

For a new roommate, if she wants to add the roommate then I’d move the rent back to market rent and run the new individual thru the same process as before.  

I currently rent in the city for $700 a month per person and would like to buy a house next year and have my roommates live there as well to pay the mortgage.

I definitely couldn’t do it with a roommate.  

That is roommate issues. 

At worst, I think I could make $800 a month on some sort of house hacking strategy - live in the main part with a roommate and rent out the MIL suite, or rent out the main house while living the MIL suite.

Acquiring roommate this summer.

This will likely be a loss, but you need to live somewhere.Now, go back to your NOI, take out your rent from the duplex (are you taking a whole unit for yourself for $1,000 loss rent or have a roommate and are only out $500). 

In the past I did deduct from other tenants that were room mates and they agreed that one person would collect and disburse the money.