Considering this, which way should bridge saddles face?
The intonation adjustment screws on a Tune-o-matic bridge should face the neck and pickups, not the tailpiece. If they’re reversed, the adjustment screw heads may interfere with the strings coming off the saddles. When this happens, it alters the string angle and can cause rattling or other problems.
Likewise, why are guitar bridges slanted? The simplest explanation is that with the slanted pickup positioning, you get more response from the treble strings and more control over the low-end strings. The closer the pickups are to the bridge, the brighter and more treble-heavy the sound becomes.