HUD loans will take drastically longer (I've never used one personally), but there can be benefits to using these loans if you're a long-term owner.The interest rates in your Key Considerations seem very low for agency loans and they're definitely low for bridge loans. 

and even then the return will be fairly low based on the risk you're taking on. 

Xeriscaping (low-water landscaping) is increasingly mandated in many HOAs, and buyers are scrutinizing water-hungry features like traditional lawns.Rising Construction CostsMaterial costs have fluctuated significantly, and labor remains tight in the Phoenix construction market.

I've also assumed VA loans where little cash was used (seller had low/no equity).

Short term (12 months), low loan to value with borrowers who have strong credit and significant assets.

Is it possible to buy a property in Seattle low enough to get 1%, yes.

Is interest so low that you can't justify having them more often?

Multifamily properties (2-4 units) can be a great way to build your portfolio while minimizing risk—especially with FHA or conventional low-down-payment options.Also, networking is huge.

I have found that the profit margins are very low in this model if the house is in a C/D neighborhood because you are limited to the amount of rent you can charge for each room.

Bank Recommendations:Chase and Bank of America are popular because of their extensive business banking features and integrations with bookkeeping tools.Smaller community banks or credit unions can offer more personalized service and lower fees, but make sure they support series LLCs.Online banks like Novo or Mercury are great for tech-savvy users who want low fees and easy online management.What to Watch Out For:Hidden fees for transactions or deposits.Limitations on the number of accounts or ACH payments.Difficulty in maintaining clear separation between the series, which could risk the limited liability protection of your LLC.Since you’re using a Series LLC structure, it’s crucial to keep each property’s finances completely separate to maintain liability protection.