Is it bad to lose strands of power wire overtime from lets say, disconnecting the wire from terminals and clamps, or even accidentally slicing some off when cutting away at the insulation? Do you lose conductivity and/or lessen amp load of the wire?

Also, would using a coupler to add on to an existing power wire to make it longer be okay to do? Or would I have to run a new longer wire to the size I need?

how many strands aer we talking here and what size wire? like if you have 5000strands and you cut off 20 i wouldnt' worry about it

as for the coupler i just use 2 ring terminals and a nut and bolt then black tap to hold it all together i DO NOT know if this is the best way but it has worked for me in the past. I hope someone chimes in and tells me what i did was okay.

allso i assume you aer talking about power wire?

they sell the couplers for a reason, make sure u get the wires nice and tight together and then i would electrical tape around them just to make sure it wont come out as easy.

Im have not use the couplers and would rather buy some new wire when it comes to power or ground wire that is the actually size I need to avoid any mishaps. Will they work, yes since they are selling but I wouldnt use them (just a personal preference).

Now if it was speaker wire then I wouldnt mind, I just dont take chances when it comes to ground and power wire.