HI, I own a part share of a nice recently renovated house in North London, with other members of my family owning the rest, left to me in my fathers estate, with probate granted in 1999, as a tenant in common.

I have been looking at properties and it seemed like the seller s  based their price on zero percent cash flow for the buyer.

How much will you spend in repairs on a 1920's house with renters ? 

My DP was around $20k and when I sold it I cleared over $200k.Good luck to you and let me know if there's ever anything else you'd like to know about house hacking.

Have a big database, sellers who look up my brand/appeal.

I see that you recommend NOT having my mom deed the house over to me in order to borrow against it.

Either one of these people - the buyer, or the seller, can screw you, intentionally or unintentionally in years to come. 

There's a tenant that's month to month, rent is at least $800 below market rent, so I told the seller I need that unit to be vacant.

There are numerous threads about sub to and many investors believe it is a high risk strategy (especially for seller) and believe buyers who use it “take advantage” of naive sellers.  

I was in a similar situation for my second house hack.