Sorting on rating is a nice suggestion, but keep in mind that rating will not move the image around, the sort will be dont when the images are first scanned and will stay for the duration of the session.
Imagine that you've rated 500 imagines in a folder, take a break, come back and loose your place (maybe the program got shut down, crash, etc.). Where do you start in again?
The program can re-open the last folder and seek to the last viewed image if the "Automatically reopen the last picture folder" option is checked (see the 6th option in Options->Misc). This solves the case where you exit the program or shutdown Windows in the middle of a session (e.g. due to empty laptop batteries).
As for crashing, FPV is used by tens of thousands of persons everyday (judging from the hits on the opt-in automatic version update check) and we did not get any crash report for months (save for one
that was caused by the user himself, messing up with his system files) so I doubt it is a common or even significant cause of interruption.
If you use the Pro version you can set up to 10 bookmarks in the image list and those are saved when the program exits. Bookmarks makes it easy to quickly jump back to a previously marked spot on the image list, no matter how many images are in the current folder tree. They can be used to mark the point where you left, or any "point of interest", e.g. a particular subsequence in the image stream etc, where you may want to return at a later time.
As you found out already, a larger display of rating/label/urgency is in the cards already. It's just a matter of finding the time but it will appear at some point in the future.