2) I know you asked for a script or plugin or whatever and people are happy to provide you with some, but the fact is that you do
not need one for that at all. You actually never ever needed one for it, and you still don't need one. See:
CookieRevised's reply to can some1 creat a script that steals the DP and puts it in a folder...
CookieRevised's reply to Where does MSN store it's avatars?
And from within the contact information panel in Messenger Plus! Live you can also save the display picture of a particular contact. Again, no need for any script or other tool for that.
3) In regards to open convo notifiers, please read:
CookieRevised's reply to Question regarding a "close msg window logger"!!
It contains all the info and links you need.
Every open convo notifier works exactly the same, this goes from the one in the old StuffPlug to the scripts for Plus! Live, and every piece of code in between. There is absolutely no difference and they are all equally unreliable! What version of MSN Messenger you use doesn't matter.
4) In Messenger Plus! Live you can set notifications for people who go offline.
As for block checkers, they do not work, link with more info already given by Menthix.