I ran number multiple times but my estimation seems not great as I am not sure what percentage I should allocate monthly expenses as the recommandation is a range such as 5%~15%.

Any advice on how to get better at estimating my rehab costs? 

By all my research and estimates, the pro forma is pretty accurate.

Do Bp still offer Rehab cost estimator?

I'd estimate 1-2 investments probable in 12-24 months.SELL Town home: we could net up to $135k. 

I estimate that the apartment building is worth in the realm of $1.8-2.3 million. 

Once the 1031 exchange is completed (again assuming 1031 compliance), I can continue to rent the property indefinitely or at any point after 2 years of rental, use it as a primary residence and thereafter living in the property for at least two years qualify to use the Section 121 Exclusion to eliminate capital gains entirely (gains estimated to be about $70 K, well under the $250,000 single filing limit).

As far as damage to wood molding I saw estimates of up to $4000 to repair...that's really high.

On point #4 I was surprised by this article I read today about older workers in the work force.https://www.seattletimes.com/explore/careers/older-workers-a... we are in structural job market changes in USA (older workers coming back, people with two jobs at all time high,etc).Next year estimate GDP growth is 0.7-1.0%Last time it happened like these was 2009.yes the greatest GFC after 2008 upon us.

This combination of affordability, economic stability, and location makes Parma compelling in my research.Taking a deeper dive into the rental market here, I thought this could be a unique investment opportunity because, despite a seemingly low occupancy rate of 23.90%, the rising rental rates highlight a robust demand for single-family homes (SFH), presenting a lucrative avenue for investors like us.The Key Growth Indicator: A significant uptick in SFH building permits during 2022 and 2023 screams a burgeoning market ripe for investment.Property Highlight: Zooming into the zipcode 44134, let's examine a promising investment with this single-family home.3104 Liggett Dr, Parma, OH 44134 On this property, I calculate an ARV estimated between $107,000 and $115,000.