For 2. you can't enter custom pairs for auto-complete (in the Auto-Insert section) with two characters. So this is not possible without a plugin. If I find one, I will update my answer.
- However, for auto closing code with semicolon ";", you can use this option and "trick" Notepad++ to not put it on every line inside a php tag (which I don't believe is a good use case), but put it only when needed. I tested with ; and ; as opening and closing tags, which essentialy gives you what you need (without the php tags check though) and it's not so nice. But if you use an opening tag of "$" and a closing one ";", then you can get an auto-close functionality whenever you use a variable (which will mean you are writing code).
Please note that using < and > or any other similar pairs will break other auto-complete functionality (including the auto-close html tags). This is certainly bad, because it would be nice to have both <> auto close and html tags auto-close.