I believe (but it has not been confirmed) that non TR can look forward to less money each month, don't know if this is due to paying back the rating, or "just because they can".
If you are already rated I would hazard a renewal might be cheaper (?) than the loss of money each month, as I guess you would be treated like a "real" non TR'd applicant & be docked the amount over 2 ? 3 ? years.
In terms of selection, I don't think you can assume anything. Our HR/recruitment Dept is not over staffed , and like most of aviation a certain degree of "fire-fighting" is the norm. . . I believe your (and anyone else's) application will not per se be less attractive, merely that on the day they picked someone else's from the list 1st, be it chance, alphabetical order/whatever. I believe it could indeed be that random.