Aye, ソー = そう. Typically I’d advise against picking a Japanese name unless absolutely required to for whatever obscure legal reason, though I’d have to admit Kazuya isn’t too bad a choice. 和矢 is harmony + arrow as you discovered.
As for the shrines, I’d say it’d be a lifelong task. There’s estimated to be about 100,000 shrines in Japan, so even if you could somehow manage to do one per hour, eight hours a day, it’d take you thirty-four years to visit them all. Good luck, though – if post your writings on a blog, I’d love to read it. =)