NEWB 5th wheel slider questions

As already posted, there are a lot of variables, but normal maneuvering is not a problem. With a 6.5ft bed, you should have somewhere between 65 and 88 degrees depending on king pin location and design of the fifth wheel front cap. Your front wheels can only turn about 36-37 degrees so when making a 90 degree turn at an intersection, the max angle between truck and trailer will be around 45 degrees. So, no problem. But beyond that you need to be careful, maybe don't turn the steering wheel full lock, maybe jockey the rig back and forth to change the angle, whatever it takes. But all this assumes an extended pin box which is used almost exclusively these days.

I've pulled many fifth wheels with GM short bed trucks since 1988, I do not use a sliding hitch and so far no problems.