Some investors prefer to start saving for these ASAP, while others plan to deal with them when they happen.The unknown is Maintenance costs, which are often dictated by how "hard" a tenant lives in a property.

Going into the unknown and buying multiple SFHs/duplexes or an apartment complex OOS and my property taxes will skyrocket (property tax is reasonable thanks to Proposition 13 in CA).

Good contractors will inflate the bid to accommodate for all those unknowns, assuming they will be coming.  

.- as yet unknown impact from required structural inspections (bill 154).

@James Carlson I do think this bill will pass but the big unknown is exactly what the new tax rate will be.

Got this from the sponsor - Real estate gain is 1231 - but there will also be recapture of depreciation which is ordinary income.With a few unknowns before the actual k-1 is released, it's hard to make any concrete decisions but was just wondering if I should sell some long-term held stock at fidelity to offset the gains

Beyond experience, make sure they align with your vision for scaling and financial independence.Finally, don’t let fear of the unknown hold you back.

Heck, you could possibly JV with one of em during those early months/years of getting going to best mitigate the unknown mistakes, experience leveraging. 

However, we have a lot of questions about pitfalls and unknowns especially with older properties, or if there is a better investment strategy since cash flow properties in our area aren't meeting the numbers we are looking for.

I understand the concept of ROE but there are a lot of unknowns.