Ever wrote to symphony orchestra??
Nope, and I probably never will. I don't have the cojones for that.
Try! Maybe it will be great, you never know until you try. And if it's not you don't have to release it :)
I've always thought Gather The Faithful would sound awesome arranged for orchestra. Why don't you try it?
Writing for a symphonic orchestra isn't something you can make up juste like that. It requires years of studies in orchestration if you want to do it correctly. A lot of artists and bands tried to write for a symphonic orchestra and totally failed imo. Only a few did it well (Nightwish with the album Once is one example). Jani is a rock/metal guitarist so we can expect him to compose good tunes for a rock/metal band, not for a symphonic orchestra :)
LOL I remember in my guitar class at high school we used sheet music instead of tabs for the last few weeks and I pretty much gave up playing along with them...