Expect them to try to play if your feelings as well, so pack them away and put under lock and key.

I am just starting out so I have a good grasp of underwriting and concepts but not a great baseline of what I should expect for returns, especially in a "House Hacking" scenario.

Not a chance in hell....Do it this time and you just set yourself up for expecting rent reductions for every tiny thing.If an issue comes up that affects habitability for a decent amount of time, then we can talk...... if you want to reduce rent for every time that the unit isn't perfect, you are setting yourself up for failure

If you end up going with a big bank that primarily tailors to conventional consumer loans... you'll get buried in bureaucracy and it will slow down your deal; but, to reiterate the key point - don't head into the relationship expecting the bank to act like something they're not. 

From a funding standpoint, you can expect to pay about 2% of the loan amount for a double closing.As far as closing costs, it is important that you have an Escrow agent that is investor-friendly and familiar with the ins and outs of handling a back to back double closing so that it is handled professionally and legally.

They don't want high maintenance JV partners who want to be involved in every little decision and may have unrealistic expectations (in terms of %return, and time it takes to complete the deal). 

If the property has any issues that would cause someone to not be able to live there (roof, plumbing, broken windows, holes in the walls, etc.) those items would come back subject to repair on an appraisal and need to be fixed before you can get any type of mortgage financing.

If I were paying cash, I’d likely go thru with it, expecting some further dealings.

I would need more info regarding the property, but you likely wouldn't need that much saved up for plumbing unless you anticipate complete failure of that system.STRUCTURE - If you think you need to invest that much in foundation and structure, you may want to rethink purchasing this property.I would recommend you speak with some local contractors to dial in your expected costs, and life expectancies of the respective home systems. 

On average I see it takes about a month to get a borrower repaying and then to expect them to make 12 consecutive payments in 12 months when they have not done it is being a little aggressive.