Hello Rono,
I think we are talking about Platinum Charge card in EU. Please correct me if I am wrong.
I would have the following feedback:
1. It makes a lot of sense to have this product in EUR rather than AUD. AU Plat charges additional fees if used overseas. Hence, local product is the way to go to minimise your financial exposure in these interesting economic times.
2. AMEX acceptance in EU is patchy at best outside of original Schengen zone. Original Schengen zone is mostly OK. Outside of this area, you may encounter issues with acceptance. This is something to consider. Your options may or may not be limited by this fact alone.
3. You may/will have to present source of income if you are semi-retired. AMEX likes to have some sort of evidence (proof) of income. If you don't have previous relationship with them, please consider. You may have to call them to discuss this aspect and consider eligibility.
4. If you have existing relationship with AMEX in Australia, why not contact AU Amex team and discuss strategies? Food for thought... AMEX is a global company and they may have resources available to help/discuss options to set you up financially in the EU zone.
I hope my perspective offers some things to consider...
Kind regards,
D