I'm looking at upgrading my home's service (100A to 200A), adding some needed circuits, like wired fire alarms, etc, and moving my service from an aerial at one end of the house to a buried at the other (since the existing location doesn't meet code for a new service).

I'm looking at putting in my new main panel (200A QO) and initially configuring it as a sub for my existing 100A service, moving the house circuits to it one at a time as I have the cycles to do so, then eventually decommissioning the current main panel and having a pro install a new 200A meter/main on the outside of the home connected to the new service from the power company. The questions I have are:

- Assuming I maintain the single neutral/ground bond in the existing panel for now, is it reasonable to put in a double-pole 100A breaker there and serve the new panel through its installed 200A rated main breaker (with 100A rated 3+ground conductors between them, of course)?

- Do I need to enclose that conductor bundle (main to sub) if it's accessible in a utility room (PVC/EMC, etc)?

- I'm comfortable doing this work, but I want to work with the city to ensure all the work meets code and is inspected properly for insurance and safety purposes, but what would you even call this kind of work? Is this one of those "ask your local code office what they think" kind of situations?

- I'll be re-routing the last 10-feet or so of a lot of older NM cable. Any tips and tricks folks can recommend for clean routing around other utilities, etc (examples of cosmetically nice work, etc.)

- Knowing that I need to add a bunch of 20A circuits for new things I do (per code) and that most of the current stuff is 15A I don't want to have to re-wire the whole house. I'd like to "future-proof" the house, so I'm thinking of doing un-terminated/shorted 20A "sub-outs" and fishing small coils in adjacent to the first box or receptacle in the existing 15A branches so they'll be there when I get the time and energy to do a lot of drywall patching in the future on those circuits (and accordingly getting 20A breakers on the other end). That'll at least allow me to close in and do all the finish work in the area around the new panel (my garage). It's not cost-prohibitive for me to do this, but do other folks do this kind of thing (or am I nutty)?

Dan