@mm77 I have gone through your travel details and it does not appear that you should have difficulty in satisfying the 330 days because the only requirement is that you find a test period of consecutive 12 months in which you have have been present in a foreign country or countries for 330 days. To exclude income you need to meet the following three conditions:
(a) that the income is foreign sourced
(b) that you have a foreign tax home
(c) you are qualified individual.
The first is established by performing work in a foreign country and being paid by a foreign entity or entities / persons. This where the restriction on being paid by the US govt or any of its administrative units comes in. Looking at your travel list I would recommend that you have documentation to establish that the income is foreign sourced ( for many expats , when they work for a large multinational, it is easy to prove the source because they are paid through a local/foreign wholely owned subsidiary established under local laws)
The Second is established through meeting the substantial presence or bonafide resident tests. Here again for at 2018, you need to be sure that your personal abode ( there can be only one at a time ) can be shown to be foreign.
The Third is established by being an US citizen / Resident ( Green Card )
Note that for substantial presence you count all full days present in a foreign country or countries and not days present in the USA or travelling over international waters. Thus when you travel from Netherlands to Germany you count all days present either in Netherlands or in Germany. However, if you go from England to Bahrain, depending on the route, you may , or may not ,be able to count both days depending on whether you are crossing only landmass or flying over international waters.
The form 2555 also asks when you established the foreign tax home and here you can always say the first of the year, if and only if, your tax home was foreign for all year but you were state side for a period on business or pleasure -- thus the foreign income for the year is based on where work performed and paid by whom NOT on your tax home. So for 2018 , if all the income was foreign, then you report that as foreign sourced and it is tax home that determines what portion is eligible for exclusion based on where work performed and paid by whom.
Does that make sense or do you need help?
my personal concern in your case would be how you prove that the income is foreign sourced and if you really had a foreign tax home because what I see is a lot of travel. Don't get me wrong on this, please
