Doesn't matter, but getting it that close would be difficult. The purpose of that fuse is to protect your power wire and protect against a possible fire. If it's 6" away from the battery, then the first 6" of your power wire is all that's left unprotected. The rest of your wire is protected from carrying too much current. The closer the better, but 1" is pushing it.
Ground wire should be as short as possible. Just select a ground position as close as possible to your amp. I'd keep it less than 2 ft. Some will probably say even that's too long.