I have done a few development projects for myself and it seems that in every one you hit a bump and wonder why.  

But I hit a wall.First: Trying to find out what similar properties in the area (10 m radius) rent for, I used rentcast and rentometer for this, but they gave me two very different results.

Every hurdle hit it and solve it.9.  

I have seen far too many times where these do not hit pro forma due to unexpected problems like theft, crime, etc.And, on top of that you are not even going to be in the US and have no ability to supervise and make sure that the people that you hired (who are not aligned with you) are looking out for your best interests.

I would pay I/O for 5 yrs, and then ri-fi but you HAVE to hit your pro-forma to execute this plan. 

Quote from @Mike H.: Its a tough one to really help someone with. 

Benefits for Real Estate InvestorsLeverage for Growth: Use business credit to fund renovations, marketing, or even bridge financing, which keeps your personal capital available for other investments.Personal Credit Protection: Business credit utilization doesn’t appear on your personal credit report, avoiding hits to your personal score from high balances.Larger Loan Opportunities: Over time, established business credit unlocks higher limits and better terms for larger investments.Potential Challenges and TipsSlow Start: Building business credit takes time.

I would say I have the experience, market knowledge and team to do this efficiently.

Well about 2 years ago that batch all started to hit and then covid money went away. 

You identify the problem (lack of deposit) during your inspection phase, then hit them with an objection that requires them to pay you a deposit at closing.