Custom Activity parameters and spaces in names



Using visual studio I have created a custom activity.
I have worked out that the class name equates to the activity name and that the folder structure is defined by the namespaces.

How do I put spaces in the activity name as you can’t have a class with a space in it?
How do I put spaces in the activity folder as you can’t have spaces in a namespace?

How do I add hover over tooltip type messages for activity parameters?

How do I create a drop-down parameter for an activity to allow the user to select an option?