| as 'or' has priority (its not 'or' for searching, its 'or' for both searching and replacement), then / as delimiter for search/replace. escapes are used only for designating appropriate symbols. i dont understand your examples, there must be even number of search/replace items. eg:
cat/dog|the/a cat->dog and the->a
if you want to use 'or' just for searching, its just generic regex (a|b), but it will require escape because | is reserved by preset:
*(cat\|dog)/red-$1 must work, will check tomorrow.
p.s. it was a good experiment, but its not usable. even you don't fully understand how to use this preset. i think 99% users wont be able to use it even with someones help.
p.p.s i'll write dedicated 'multiple search and replace' command (frontend for this preset).