Dude
Now 24, After NS 26, After Honours year 27. CFI 1~2 years 29. You will be fine.
Tell me where else you can go with your CASA CPL. Nowhere. Nobody is hiring in Australia. At least in Korea, jobs are always there but you have to compete with other 250hrs guys.
This advice comes from a guy who is doing civil service now whilst fixing my body (yeah I got level 4)
after flying heavy turboprop in overseas.
And I told you above, you won't be able to join KAL or AAR through agencies because you are an ethnic Korean even if you have 5000 hours of jet hours.