Assume a couple of months of vacancy, consider potential unexpected repairs (like HVAC or plumbing issues), and test the numbers with rents dropping by 10-15%.

This is a "me" assumption: I assuming that I made a mistake somewhere in my analysis, so please feel free to show me. :) I learn a lot more from my mistakes than what I (very occasionally) get right on the first pass.

You'll want to get a tax estimate if you sold in 2024 so you can pay in the appropriate amount of tax (Assuming you didn't do a 1031 exchange).

I'm hoping things move a little more quickly once things go vertical as I heard getting slab poured is the longest wait but I'm assuming there is a labor/material shortage in general in the area so wasn't sure of people's timelines once slab has been poured?

You would assume that sellers know that they should optimize NOI before listing, but most don't and STILL want you to pay a price based on what NOI could be.

Never Assume anything. 

I assume their realtor knows they wouldn’t and therefore isn’t going to bother submitting your offer.

I'm assuming it's at least $500.

However, a simple security system would deter this.Personal Safety -  I assume you are using their ID to run a background check and deciding if their history affects your safety, correct?

Based on your question, I'm assuming you're looking to flip this property rather than rent it out, is that accurate?