Looking for any input on some general questions...Some quick real estate background on me.I have one rental property 90k in equity, zillow estimate of home value is 200k and about the same in equity in my current home, zillow estimate 290k.  

Don't want to put ALL my faith into my Excel spreadsheet for the return estimates without running it by a few people.  

I had a feeling that I've under estimated the repair/maint cost.

Always over estimate your expenses, and then add 10% onto that for a reserve, and then add more for fun.

How much renovation is needed and what is the estimated cost of that renovation?  

Scott book Estimate Rehab Cost ( I believe that is the correct title check to be sure) was mentioned in the webinar.

Estimated completion time of 7 months.

Estimate repairs?

Then, look for a contractor to offer an estimate on a new con bid.

Since you want to do flipping I also recommend the books on rehabbing and cost estimating by @J Scott You can find them in the BP store under the Resources tab above.