They have better rates and we are ok buying in our personal name for a single family.

Now, you still have to comply with all of the standard 1031 rules -- including (A) buying properties that are at least as valuable as what you sell, and (B) moving all of your equity from the STRs into the LTRs -- then you may still pay some taxes even with a 1031. 

I wanted to ask the forum to hear personal experiences from those who have managed flips remotely themselves without a GC and how it went?

Personally, I would get the duplex.

Investing in one asset class and 3 syndicators is like investing in delta, United and American AirlinesIf that asset class has a funk, then so do you.This is a personal preference for you - but owning real estate - especially a str is like running a new business and is not passive

However, the presence of personal items like clothes, a suitcase, and a pot on the stove inside the RV raised red flags.

You'll likely start to gravitate towards one type of investing based on your personality, then double down in that area. 

If its a 2-4 unit you only need 15% down using a True Portfolio program and you have DSCR as a back up that uses the STR rents to qualify and avoid personal tax returns or income.  

I personally believe it's smart to get ahead of the curve of this trend before ADU's become more of the norm in AZ.

Consider consulting with a real estate professional or financial advisor who can provide personalized guidance based on your specific situation and goals.