1) These two items are completely different and have little relevance to each other.
Using . (ie: .notice) is the same thing as using /notice, except for the fact that the . makes the command silent (handy if you're making a bot with a lot of commands that don't have to show on the bot's screen)
The usage of the braces { } allows mutliple lines of commands for a single event or condition.
2) I don't understand where you're getting the 12 from as the C character (actually called the token delimiter), as I used 32 (which is the space character).
3) Your first idea is correct. It has little to do with what the person triggering the code types. As long as they type + (or -) as the second item (space separated) in the line, then the code functions.
Items typed in are always presumed to be space separated for most mIRC codes that use entries, as it is the easiest method.
I have written codes that allow people to enter multiple items using commas and/or spaces, but most people (when typing) use the space bar between words automatically.
