I dont do 100% development but have done my fair share over the years. 

Hi @Helena Goyvaerts,Investing in the US from a different country is fairly similar to investing as a US citizen, but there are a few differences and a few things to keep in mind.1.

I too live in Marin, and feel it is a solid long term market for apprecaition, and utilizing the power of principle reduction.When it comes to refinancing, figure out what the loan costs will be, then divide that buy the monthly savings with the new loan in order to determine how long you have to maintain that loan to break even. 

What percentage is fair to pay sellers agent commission and would I be expected to pay buyer agent commission as well?

I find that depending on the market $300-500/mo are fairly normal and if compared to what you would pay with a single family home on some utilities, maintenance, and management, it's a good deal.

I own a commercial unit, and I’m trying to determine a fair rental rate for the space.

Gains within this account are tax-free if rules are followed, but avoid prohibited transactions to maintain account integrity.

To thrive in real estate investing, you must maintain a firm grip on your finances.

Be prepared for the learning curve with Detroit—it’s rewarding but comes with its fair share of challenges.If you’d like more specific guidance or have questions, feel free to DM me.

Even if they did, the side with evidence tends to win.Your deductions seem reasonable and you are clearly trying to be fair.