If you have a different gear ratio front to back DO NOT lock the transfer case and try to drive around. Something would have to slip, and best case scenario would be tires. But it would put a ton of strain on everything.
However, with the transfer case unlocked the front driveshaft will spin a different speed than the back while you drive, but the wheels will not be spinning (or trying to spin) different speeds, and should not mess with ABS or traction control.
I know some of the auto-lockers click when turning, but we have no idea how much yours are clicking to say if it is normal. Any chance you can record a short video of the sound?