I have either Kuwaiti Dinar (1 KD = 2,83€) or Omani Rial (1 OMR = 2,25€) in which both are of high value. However will money changers in Europe accept that for Euros. For example: the highest bill from Oman is 50 Rials (112€) & from Kuwait is 20 KD (56€).
Of course, currencies from the Gulf are petro states (like Kuwait) have higher exchange rates. Should I bring those currencies into Europe or convert it (for USD) prior to travel? Also, will I be able to bring 6000 KD (16,960€) in cash?
There is no clear advantage to selecting a currency. The value is the value, and with War in the hood, values can swing wildly over short periods. Pick one, live with it.
The important question is where can you get the lowest transaction fees for the exchange. This can vary wildly and you can directly control how much you pay. The money changers, like you’ll find in an airport are like the convenience store version with eye watering rates. Whatever domestic bank you use for daily banking will often offer major currency exchange for an almost reasonable fee as a courtesy for their good customers. Going to a bank you aren’t a customer at, they will often charge a higher fee.