With the GRP you do not declare any of your
global income to the Malta tax authorities - only the amounts that are remitted to the country, so basically for us it's the amount for the prepaid minimum tax, the rent, and fees for our agent. We don't bring any other
cash into Malta and therefore only pay the minimum tax requirements.
As for the TRC - our agent says they can get one if we need it and it's a legal tax ID from a sovereign country. But as we notified the Australian Tax Office that we were leaving the country and no longer submitting tax returns, we haven't needed it. The key is whether you'll pass the "closer connections" test (or whatever residency tests you have in your home country). We have no property in Australia and we rent a property in Malta - plus we have Malta residence cards, tax IDs etc, so we feel pretty confident with our position.
The added bonus is that with the
Malta residency card - we can skirt around the Schengen rules because we don't get stamps in our passports anymore.
It's a good option if you want the flexibility of a pretty good tax residency without a huge capital outlay and no requirement to be in the country.