Correct.

You can select from your primary or secondary CC details. FX charges apply (which is never in your favour)

Basically it will charge USD100 only. What the FX means is Foreign Exchange rate.
Means when convert back to RM, it might be higher or lower.

Example,
if the Exchange Rate = 3.6 you need to pay RM360
if the Exchange Rate = 3.3 you need to pay RM330

Hope this help.

You can do unlimited transaction/day but there is a limit on sending money/day.
5 times transaction/years is refer to accepting CC payment.
While accepting PP balance is unlimited/year
No need to upgrade to premier account coz you can have 2 PP account 1 for personal used and 1 for biz purposes