Instead of creating a Rolling Title, instead animate that with Keyframes on the Fixed Effect>Motion>Position. You can then "hold" the Title, and, at the point you wish, have it continue, or maybe go off-screen in another direction.
how to freeze the last line at screen center (while the rest of the roll moves up off the screen)
Do you want the text to split? Last line stay put and the rest goes up.
That is going to take two titles.
If you just want it to freeze and fade:
Give a couple of enters to the text in the roll/crawl options so the last line is in the middle.
Then set the postroll to a value (frames) that will last the freeze and the fade out.
Well, being basically a newbie to Premiere Pro (CS6) I felt forced to say duh? Where can I find the roll/crawl options or associate keyframes to a roll? I hate soundig stupid but...well...