These are both somewhat common problems with many VPI tables... the chirping noise upon startup is just the belt slipping until it gets the platter up to speed. It doesn't cause any harm but can be eliminated or minimized by powdering the belt with talcum powder. You simply place the belt in a ziploc bag with some powder in it and shake it around to lightly coat the belt and remove any excess powder, then replace the belt on the table. Problem with this is you'll have some powder fall onto the table for a while when you run it which can then be dusted off. Otherwise you can choose to just live with the chirp and avoid the powdering routine.
The pop when switching the motor on or off is a compatibility problem in some systems, and VPI says it can commonly be prevented by swapping a capacitor in the motor housing as detailed in this
VPI video.
Hope that helps, enjoy your Prime Signature!