Scarey, Scarey!!!!!!
This is a fast way to trash a guitar. You really have to be patient, and plan this out right before you start cutting.
Get some poster board, mechanical pencil, your bridge and a yardstick.....
You need to draw out the side view with the bridge in hand, so you know how high it is to the top of the saddle.
Draw a long straight line- that is the string..... below that, draw a parallel line for the fretboard, taking fret height and string height into account..... mark the nut and the scale length for the bridge placement, and measure the height of the bridge..... and viola.... you found the baseline for the bridge...... and you can change the amount of neck angle by shifting the point of where the neck/body join is.....
Find a neckthru FAQ if that didnt make sense. It'll probably explain it a lot better.