Can I have an action only pertain to a certain object type, and if so how, do I have to have the object type in #'s or something else?

#'s are used for variable names that stand for something else. Object type names don't change (they are not variables) so they do not use the #'s.

#'s are not used for the Object Type name. eg. (in QDK) Game: Object Types: Add: edible: OK

#'s ARE used in the command that calls the action. eg.:

(In QDK) Game: Properties: Edit Custom Player Commands: Add: eat #@object#