UIActionSheet is more of a way to communicate how the menu is presented. UIAltertView, for example, is presented modally, but could have the same elements as the UIActionSheet.
Having said that, if you are looking for the most generic way to describe a grouping of function/method calls the user can interact with to make the system do something, I would go with "menu" - the details deal more with presentation than anything else - modal, non-model, drop-down, toolbar (menu/navigation), site navigation (menus), etc. So, in the case of a "toolbar menu" - the presentation is generally icons with optional text (the toolbar above the Stack form, for example).
Window, is a method of presentation. Sheet, is a method of presentation (in the case of UIActionSheet - it comes up from the bottom, similar to a UIView presented modally; however, does not, generally, cover the entire display and, to the best of my knowledge, cannot have scrolling capability). Form is generally used to specify a way for users to input data/information - name, address, etc. for a contact "form".
I'm not sure what you mean by "switched out". Hope that's helpful.