It's been a while since I watched it, so I don't remember clearly, but I did wonder about the same thing at one point. I think I didn't end up changing it because somebody said in-series that they were twins. Try checking the episode where their flashback tells how they met the Wing Engines. However, I really doubt the actors' ages matter.

I can see their names clearly on the jackets. I don't understand why they wouldn't use "Hanto" for a fully Japanese name with Kanji, but sure, go ahead. These iterations are reasonable and understandable enough. If the character list has most of the name coinciding with official names, might as well.

It's probably for the symmetry on the jackets. Same reason it's "Renn" and not "Ren"