Engineering Technician

You can go for New Zealand. It will be the best option for you.

No, I do not think direct entry into the 2nd year would be allowed in most institutions. Lateral entry into a different college is only permitted once you have begun your course in B.Sc and have completed your 1st year in B.Sc. You can then apply for lateral entry into a different college in your second year.

Yes, you should be able to pursue B.Sc in radiotherapy after your Diploma provided you meet the minimum requirements to gain admission in B.Sc.
B.Sc Radiotherapy eligibility:
1) 10+2 (Medical) or equivalent with 55% marks.
2) Few institutes conduct entrance exam for admission.

Some of the M.Sc in Aircraft Technician courses which you could opt for are as follows:
1) M.Sc in Aeronautical engineering
2) M.Sc in Air Transport management
3) M.Sc in International tourism and Aviation Management
4) M.Sc in Air Safety Management
For a detailed list, please check online.