Agree on this. Apples warranty works on a global level SLA so you’re good on that. Just keep in mind the applecare terms as mentioned. Perhaps get a second opinion on an apple store to check if it’s possible to change the location of your applecare plan

M2 and M3 is almost the same performance wise with around the same bandwidth limits 100gb/s vs 200gb/s. The M3 Pro is a different beats with 400gb/s and that’s where you see the big improvements especially having more performance cpu cores and gpu cores. If you have the money to spend the best investment for 5 years is the M3 Pro but if price is a concern than M2 Air should suffice for 3 years until the M5