Answers
Given that you are not a Greek tax resident (if my understanding is correct), you do not have such obligation. You would have only if you had income that you earn in Greece. But since this is not the case here, you do not have to declare something here.
Please be aware that since you have a property in Greece and also professional activity, you are obliged to pay taxes for the gain activity as well as for the property. For more details you may advice an accountant on this.
Of course not, since you are not a Greek tax resident. Besides, the related services were delivered abroad, independently of the account. In the case of you being Greek tax resident, your taxation is being settled in Greece under the terms of the double-taxation convention between Greece and your home country.
No, you don't have to pay taxes on your foreign income as a Golden Visa holder. You would have to pay only in the case that you were a tax resident of Greece, with the prejudice of the bilateral double-tax avoidance convention between Greece and your country.
Definitely not. Taxes ought to be paid for income earned in Greece.