I recent l bought a CU7 and I was wonderinng what angle of a edge you should put on the blade. On the care guide that came with the knife it says to put a 10 to 15 degree angle but isn't that to narrow for heavy use. And also my altoids can doesn't fit in the sheath because of a small elastic band. In the care guide it says that the knife is prone to rust( Because of the the high carbon steel ) <img src="images/graemlins/confused.gif" alt="" />, is this true?