I think you don't understand number 3.
instance variables are predefined values. Dictionary is used for dynamic values and use for long term storage(Dictionary to WebStorage).
as an example if you had a game where you hire squad soldiers, but you can name the soldeirs, have a varying number of soldiers, different stats, gear so on. Dictionaries can be very helpful to organize the data. Where as instance variables have very limited use for such dynamic storage.
4. yes. daily, every build. constant.