What are some red flags ?

The American economy and sentiment would never support that.

That raises a ton of red flags to me.

Did you know that for most Americans, taxes are their highest expense each year?

Also remember the time these returns will take to amend along with the possibility of opening up audit periods/red flags with the IRS due to amendments.Doing this yourself on turbo tax likely won't be your best bet considering all of the details.

Similarly if you feel the material pricing is marked up by too much, that's similarly a red flag.

I just finished their taxes with their CPA and I can say from first hand knowledge that real estate is the most effective way for immigrants to obtain the American dream.My parents immigrated to California in their 20's from Asia with no money, and could not speak English.

If he lived in the same place for four years, that should reflect on his credit score.I think you've found enough red flags to justify denying them.

The reality is that the new generation of native-born Americans don't want to build houses, they all want cushy high-paid jobs in tech or finance etc. or to get rich quick off of crypto or being a youtuber or running internet businesses, etc. very few of them want to work in the trades. 

Additionally, these investors can provide warnings about potential red flags, ensuring you hire reliable contractors and property managers.