can I do "store.init" in each scene's "createScene" event? (i.e. only need once for multiple requests?)

I have some questions around “store.init”

a) Is only one (1x) “store.init” required, after which you can do multiple requests (e.g. purchase, restore)?

b) So finalizing a transaction (i.e. store.finishTransaction()) will NOT clear your “store.init()”?  (i.e. don’t have to do another “init” after finishing a transaction?)

c) Is it OK to do a “store.init” in each scene’s “createScene” event? I this ok?  (i.e. so no matter which path the user takes the init would have been called).  The question therefore is it ok to have multiple “init” requests occur?

d) following on from c) is it ok to have multiple “store.init” occur, for which some do NOT have a transaction that actually gets called on it?