Do this mean I would be putting the pseudo pin wherever I would put my normal pin (i.e. say 1:30 above ring finger??
Yes, You would use the pseudo pin as you would the normal pin.
Wouldn't this put the actual pin on the backside of the ball and potentially have the core upside-down?
Yes,
It doe's place the core "Upside down", because it's rotated the core 180 degrees and the normal pin is on the backside of the ball.
That's what this part explained
(*1)When a ball is rotated off of a bowler’s hand around their Positive Axis Point (PAP), gravity will constantly pull at the top and the bottom of the ball. As the ball
rotates, gravity will equally affect both the positive and negative X-axis.
In bowling terms, the manufacturer’s Pin marks the positive X-axis. Likewise, the negative X axis is referred to as the “Pseudo-Pin†because it is 180 degrees opposite of the ‘normal’ Pin.
Since both the positive and negative X-Axis will encounter the same gravitational pull equally, it does not matter if ball is drilled using the regular Pin or the Pseudo-Pin so long as either have been properly orientated to the bowler’s PAP.
As for how the MB factors in I don't know.
I would weigh up the ball and spin it up on a determinator to double check CG and MB locations before doing anything.
I would spin the ball and find the MB first, I think the pin or MB is probably mismarked. the pin and the MB(PSA) should be 6 3/4" apart.