Operating expenses would need to be provided by the owner and may not fully reflect everything.

It's more expensive, but has significantly less paperwork, requires little to no income documentation and the construction financing will be paid out in draws.  

Tons of labor & laundry expense.  

In 18-months the damage will be somewhat limited and {hopefully} will not have had the opportunity to permeate the subfloor and structure {though that is a possibility} - you may just get away with a lots of cleaning and replacing finish flooring (like carpets).The longer they stay, the more expensive the repairs will be at move out.

Even my $3,360/yr maintenance budget feels a little low to me based on the rehab to be done on the first floor.Now, when I plug these numbers into the calculator referenced above (including an 8% vacancy and $280/mo for repairs and maintenance), I can see that you'll have monthly expenses of $1,640.  

I'm considering starting an LLC that I can run rental income and expenses through for the main purpose of starting a retirement plan (probably a solo 401k) so that I can start socking away some income into a tax deferred account.

East Rock appears to have some serious potential East Rock is a wonderful neighborhood but very expensive to get into.  

The stucco on house is old and in bad shape so probably needs to be removed or vinyl side over it.Question: If I decide to an an offer how much should I budget for repairing this and how complicated and expensive will this repair be.

I'd like to self-manage the first rental as a learning experience but would eventually plan to transition to a management company, so the numbers have to make sense to cover this expense.  

The $840 mortgage and expenses are covered nicely by $750 in rent (housemate on my primary residence) and $1550 in gross rent on the duplex.