1) What is the difference between symmetric and asymmetric coils on both a practical and tonal level?
2) What is the effect of offset coils?
disclaimer : the following is what I understand so far and cab be at least partially wrong - please someone correct me if/when necessary ;)
These are really the same question AFAICT. A humbucker is two coils wired reversed phase / reversed polarity (usually series but it also works in parallel). The reversed polarity is supposed to cancel the effect of the reversed phase so hum is cancelled but signal is not, in real life it's a bit more complex partly due to both coils not being in the exact same position so you always get some phase cancellation AND some summation happening depending on the frequency, exact winding and whatnot - IOW technically a
comb filter.
Practically, using an offset coil (aka asymetric winding), you have a bit less hum-cancelling, a bit less of the comb filtre effect hence a more even frequency response, and since one coilhas more output than the other you also get a bit more of a single-coil tone (but the first and main difference between a SC and a bucker still comes from the series wiring and - if you define SC as "Fender type SC" - the internal architecture of the pickup, ie metal plot over a magnet vs magnet plots).
Now I'm already far out of my confort zone so I won't even try to address your other questions :lol:
