or use another finish to keep free from rust? im considering this after some stories i've heard and pics i've seen. im good abut cleaning but i dont want ti to be a problem.

Is it safe to cold blue the inside of a bore and the outside?

I don't think Cold-Blue would offer enough protection.  I'd look into something a bit more extreme, like cerakote or melonite or IonBond.  You could parker it too...i guess.

The thing about "rust" on a Kimber is the barrel is "in the white" or doesn't have a finish on it.  A little oil and steel wool on the outside of the barrel will keep it good, and some SS polish will really keep it shiney and new.  You could also apply some grease to the outside of the barrel to protect it.  

As far as the bore goes, I wouldn't worry about it, just keep it clean and oiled.