Job offering in Hai Phong

I am a US citizen.  I had an offering in Hai Phong that the company pays my monthly salary via a holding bank in Hong Kong.  Along with salary, they will provide local health insurance housing and driver etc .  I don't want to move to Hai Phong permanently.  Currently, we have agreed that I will work in Hai Phong two months and working in the US 1 months... the rotation will continue like this basically every quater.  Company will pays for my economy ticket each time.  I am totally new so give my ignorance or etiquette.  Here are some questions and hoping expat experts can help:

1.  With current work schedule stated above, is this mean I am a residence of Vietnam or non-residence.  Is there a work around for this residence or non-residence i.e businsess traveling.
2.  If I am qualified as residence/non-residence, I am assuming that I will subject to local taxes, right?
3.  Follow up with question #2, this mean I can not file for FEIE (Foreign Earned Income Exclusion), correct?
4.  If question #3 is correct, is this mean I have to pay double taxes?  Any work round this? 
6.  Any local tax accountant in Hai Phong you can recommend?

Thanks in Advance!

With all the travel restrictions and I don't know of any direct flight from US to VN, most if not all of the layover cities have been banned, how do you plan to go back and forth every quarter until all the bans have been lifted?

All relevant qnbui.  Let just say, there is no bans cab you help with 4 questions?  Thanks,

Can not cab.....