For question #1, post a close-up pic of the marking just in front of the serial number. I could tell you then. It is from the Nagoya arsenal.
I think on the bolt, someone may have tried to close the bolt with their finger on the trigger?? You know, like on a Mauser, where you hold the trigger while pushing the bolt forward, so that the rifle cannot be dry fired. You do that on an Arisaka, it can bind up something awful, sometimes even breaking the safety. Sorry Firing Line, but go the the Japanese board on Gunboards. There are some very knowledgable guys there that may help.