When I comp a rental, I use the biggerpockets rent estimator then I follow it up with a call to a local property manager to verify that's an accurate market rental rate. nothing will beat calling a property manager, they have all the information you will ever need or want to make your final decision about a property.

Ask the lender for a fees worksheet or loan estimate to see the breakdown in fees.

How long for a make ready estimate?

In the process of securing estimates from GCs to develop a total cost for the project.

Yes I think you'll find tenants--take a look at rent listings and rent estimates on Zillow. 

They aren't relevant estimates, they should not be taken into consideration in decision making. 

My loan officer said because they are in forbearance they will need to estimate a 1% payment (>$3000.00) per month.

But until the K&T is removed and replaced with Romex, the contractor could only give me a rough estimate of $5K - 10K .Challenge #2: There may be other issues that come up once this is permitted and the City becomes involved.

Best to just use the estimates as a guide and then get in there and do your own work from there.  

I only have two rentals and this is my current formula for annual rent increase for current renters.The greater of 4% or 1/4 the difference between current rent and Zillow Estimate not too exceed California AB 1482 which is capped somewhere between about 7% and 10%A concrete example:Current Rent $2937Zillow Estimate $35924% = $30541/4 Zillow Diff = $31015% base + 6% CPI cap at 10% = $3231In this case the increase would be $3101Note my rentals are EXEMPT from AB 1482 but I do honor this because I believe it is the right thing to do.