I emailed Edgar their sales manager, about rust and polishing and this is what he said:
I live near the ocean too.
You should spray some anti-corrode inside the pipes. and when you install the pipes to the heads, it is a good idea to put some anti-seizing. Any auto-parts will have that. The anti-seizing helps to keep the two metals (the pipe and the headers) to stick to each other after a long time due to heat. It is much easier to remove the pipes later.
To keep the Aluminum shining, you could polish it with aluminum polisher every two or three months. Aluminum is a light weight metal, but gets more scratches than steel.
Just get the correct polisher - Specifically for Aluminum - If you use other metal polisher small scratches might occur.
But the pipes should last a long time. I have in my racebike a set that I installed 3 years ago. they still look okay and I abuse of the bike as I race them hard...
enjoy your EX500.. a fun bike!
Edgar
PS; Anything you need, do not hesitate to contact us.
Speedbike Racing Inc.
Edgar