No, you just use the variable
Latest versions of Safari and of OS X? Can you take a screencast?
Looks like you decided to go with a Marketo form only. Not a bad idea!
In any case what I'm referring to is simply that the only parameter of a ready/whenReady/whenRendered callback is already a Marketo form object. You don't need an intermediate variable, and you don't need to refer to the allForms() collection, which creates unstable behavior.