We have recently moved into an old house (circa 1950) with much of the original wiring (not K&T). The previous owner(s) had done all sorts of weird and wacky things to the house, and we are slowly discoving them and correcting them. Most of the electrical wiring is original (paper insulated Romex without grounding wire). I have a question related to the recent discussions about shared neutrals.

I've found out that 80% of the house is wired onto 2 branch circuits with a shared neutral!! What looks like 14/3 wire (without ground) is connected to 2 (adjacent) 15A breakers that are not tied together with a handle cross-bar. This wire runs to a junction box in the basement and powers (with a shared neutral) 2 branch circuits. From there multiple 14/2 wires (without ground) run out to various parts of the house. These 2 circuits supply power to lights and receptacles throughout the house.

I'm not happy with this situation and want to do something to reduce the potential load on the single neutral wire. This is what I propose to do:

I plan to split off as many of the end run wires as I can onto newer circuits that do not have a shared neutral. I should be able to split off enough wires such that one of the 2 main circuits now has no load at all, making it redundant. I plan to take the hot wire from this circuit (which now carries no load) and convert it into a ground wire (tagged and labelled) for the other circuit. This will free up one breaker slot for a new, properly wired circuit. The remaining circuit now has a dedicated neutral, a greatly reduced load and is grounded at least as far as the first junction box.

Is this a reasonable thing to do? Thanks in advance for your opinions!!