#1
is it possible to have a push pull switch change a pickup to out of phase?

if so, does anyone have any diagrams for this?
#2
Yes it is.

Single=
http://www.seymourduncan.com/support/wiring-diagrams/schematics.php?schematic=phase_reversal_singlecoils

HB=
http://www.seymourduncan.com/support/wiring-diagrams/schematics.php?schematic=phase_switching_for_hb

Look around the net (google is good for that kind of thing) there are loads of sites dedicated to guitar wiring. Seymour Duncan has a lot of other pp options as well.