I just did my own house and...
- your knob and tube are kinked in insulators inside your walls and are run separate through the home
- you have lathe behind your plaster. you are in for a real treat
- you need to replace your drop service (from the main power line),weatherhead, meter socket, panel, and ground everything first
- you will trace nothing with any non contact tester, you will be cutting holes or gutting it
- check if you have galvanized pipes. You want to replace those trust me. They are FULL of rust on the inside. That will give you some openings to run wire upstairs. Then wire the 2nd floor from the attic. Outside walls are going to be tough but your house is balloon framed so you basically have a chimney between each stud that goes from the basement to your attic. Should put some fire blocking in there. Look it up, it will save your life.
- your breakers are not on rooms. you will have west wall living room, north wall kitchen and dining room light. The wires will be soldered together in places, you will see in the attic floor.
- You cant combine new and old wire first of all. Doing the downstairs you will loose power to upstairs the way the wire was ran back then. Your hallway light on the steps will not work because it's a 3 way and you have one 3-way up and one downstairs.
- You have no grounds if you have knob and tube as well as metal boxes (crazy right) The number one thing to be weary of is you can not lose a neutral or your house will most likely burn down. Your insurance wont even cover knob & tube as in they will not insure your home at all unless your removing it.
- adding shut off panel near the main meter...that becomes your main disconnect and everything after is a sub
- You need to call a licensed contractor and don't worry about your stud finder gadget and messing with any wires. Your panel switching plan needs to be revamped because if your grounds. It makes more sense to drop your SE cable to a main service panel in basement for multiple reasons. You have to have floating grounds to your subs, the wire to run to a sub upstairs...idk my friend. Your 300 amp is not going to happen, what the heck are you running a machine shop? (joking) I want you to be safe. They will do all of that for you, cut the smallest holes so the plaster keys don't break and pop off the wood lathe.
It is a big job and your safety and family or friends safety is important. If you do have romex from the 60's it can have asbestos in it, there is tile with asbestos and pipes that may be wrapped in it. I wish you the best of luck and you will see what I am talking about.
p.s. Check your bathroom stack. Now would be the time to get that cast out of there. It probably runs down your staircase wall from the second floor to the basement. It's not if but when that begins to leak because its rusted you will have a mess in those walls. If it is pvc you are blessed.
Love my old home (1913) with the oak trim and doors. These houses lived over 100 yrs and after upgrading and insulating, a 100 more.
Have fun and stay safe!