Kaptin M...theoretically, per the contract, you have to live in either Australia, NZ, Singapore or Hong Kong (to minimise time-zone changes when you commute?). Otherwise you must have the permission of the company to live elsewhere. Some guys do - Europe, Malaysia, Rarotonga.
Ah, the 'base'! Initially, AJX anticipated the 'base' was anywhere in Japan - thus no allowance would be paid whilst in Japan! Our understandanding was our base was one nominated airport from where we were primarily rostered and kept most of our belongings/suitcases etc. Thus contract was changed to reflect this, so, if you are NRT 'based' (for rostering purposes - not where you are domiciled) you get no allowance whilst in NRT but you do if you spend a hotel night in KIX (or HNL or HKG). Theoretically, if you spend the whole month operating out of your 'base', you will get no allowances (except for the commuting and 10 day accomodation allowance).
Have not heard a peep about Parc or HACS paying any tax for us - wishful thinking!