it is totally possible if you take your time and plan out the schematic...just make sure you know which wire is the north end or south end of the magnet of each coil otherwise you make get some funky sounds or none at all...
personally i'd make the coil 2 & 3 option a coil 1 & 2 in series, there just isn't much tonal difference for my taste compaired to coil 1 & 3...but you have final say
All that is possible EXEPT position 1 (coils1 & 2 in parallel).
The stock pups are wired in series and can't be modded to parallel, i tried to do it and failed.
The 20th SR5 is designed to do something like what you want.