I’m currently evaluating whether to go with a Fund Model instead of a traditional JV for an upcoming multifamily project, I will be working as a developer looking to do work with a more experienced developer on a larger scale multi-family opportunity.

Given the scope of your work, a simple plumbing leak would not concern me, it's a $200 issue at the most and ideally, it's just another line item when you do rough in plumbing for the kitchen.Being in a Milwaukee suburb, I am guessing it's a 1960s ranch, probably with galvanized plumbing.

Traditional mortgage?

It would cash flow nicely.One item to plan for from the beginning is the exit. 

Basically almost all the items you mentioned when traveling can be written off to a certain extent.

Often, traditional lenders offer better rates, which can significantly improve your profit margins.2.

The reason sellers cannot sell these properties through the traditional market is often due to certain issues, and 98% of the time, these issues are not beneficial to you as a buyer.

Will likely take longer to close than a traditional hard money (they have to order an appraisal, satisfy lender conditions etc..).

When an owner replaces or retires certain items (e.g., lighting, HVAC, or carpeting), they can claim a deduction for the remaining undepreciated value of those items.

I agree that DealCheck (or the BP calculator) does not provide enough tools or functionality to analyze those types of transactions (yet).But I would argue that it does a great job at analyzing more traditional buy & hold SFRs and multi-families, as well as flips and rehab projects.