Best tool is AE but it can be done in Premiere.
For freeze frame read this section.
The best result is accompished with Timeremapping.
For the circle you can draw that in the Titler with the pentool.
Graphics type will be an Open Bezier and set Cap Type to round for round corners.
And animate it on the timeline with Radial Wipe.
Then nest the circle and reverse the speed in order the get it drawn instead of wiped.
Make sure 1st keyframe of the Radial wipe is not at the beginning of the title as the circle will disappear too soon at the end.
Cool. I shall give that a try
As for Ae, I've just opened it up. What would it involve in that? I'm just having a look through, and it seems to make sense! (famous last words!!)
Ann has you covered for drawing a line, but is that really what you want to do, or will a simple circle or oval around them be sufficient? Because if all you want to do is simply call attention to them, it is very easy to create an outline of a shape in the titler and just fade it in over them, and then fade out again.