I don't use the calculation tools as the ones I have are more comprehensive.

I am guessing these bidders have not run any ROI calculations and are paying an auction premium too? 

Use the BP calculator and repost your analysis 

Regarding your PM, if you are 100% sure on the rent value that you're using for your calculations or that you're "in" for purchasing it regardless, then you could wait until you have it under contract to loop them in. 

First and foremost, I have to wonder how you are calculating cash flow.

If there's something your not sure about in your calculation, that's the next topic for you research

After a major renovation I feel much more prepaired to calculate rehab cost.

If you're not familiar with the 1% rule or some of the other rules of thumb definitely look those up because knowing your numbers and budgeting for them will be very important (use the BP calculator!)

BP has various tools available to help you analyze your deals (rental, flips, wholesale, etc), feel free to use them: https://www.biggerpockets.com/investment-calculators

The first one is trying to negotiate 1 month free rent while the 2nd one wants to sign already with no demands.The second one came in for viewing and the only thing is was curious about was the Electrical Board(Calculating the amps to make sure it was not 60 Amps and that it is 100Amps).