The RIMS and Kettle will never fire with each other just the RIMS and the HLT will. The RIMS and Kettle are on a 3 way switch to make sure no accidents will happen. I also have some more #6 if you think I should use it to jump all the breakers.
Should I replace the neutral wire with smaller wire? I have some #14 white if I have to do so.
Yeah I remember talking about the 3-way switch now. That will be perfect, I would just leave it.
Yeah could replace it with #14 if you want. It won't hurt anything the way you have it now. The #14 is just easier to work with and takes up less room, but you have it done now.