1) according to your situation, there is still a chance that the schools in foreign countries will accept you. But since the FD/DVE is only equivalent to form 5, I would highly recommend you to continue grade 12 [form 6] in private high school in foreign country
2)
cheapest tuition fees + living expenses: australia, new zealand
moderate tuition fees + living expenses: canada
expensive tuition fees + living expenses: USA
[if you want some information about schools in the country that you want to study, we can discuss it via email or messenger]
3) for 國家福利, i would say that international students will not receive any 國家福利 from the countries but the local students, such as financial aid
if you have any problem, email me:
[email protected]
hope these information can guide you to a successful path