My understanding is that library submissions are supposed to be on the quiet side and lightly compressed, in order to give the end user more options. A highly squashed master might get passed over if squashed isn't what the buyer is looking for. So yeh, you're probably on the right track keeping it dynamic with lots of headroom. 14db of headroom is perhaps going a little too far in that direction, though. I'd think that limiting peaks to -6db would be more than adequate.
If you're looking for consistency, e.g. getting tracks from similar genres to match, you're going to want to look at RMS rather than peak values. Set the absolute limit in Ozone to -6db and let Ozone take care of it. All you have to do is make sure it's not pushed so hard that it sucks the dynamics out of it.
If you find that the maximizer is working too hard, lower Ozone's Input fader. I've had mixes where I let fader-creep get the best of me, resulting in a too-hot mix that required lowering the input to Ozone by 6-8db in order to give it some room to do its magic. For example, if you're trying to limit peaks to -6db, but your levels going into the master bus are averaging -3db, then Ozone's going to have to be working constantly and you're at risk of losing dynamics.
I'm an Ozone fan myself, but I actually use the free Voxengo SPAN plugin for K-metering. Put it into Mastering mode and select K-14 for the meters. What I shoot for is to have the meters hovering around the zero mark, going no more than 4-6db below it on the quietest parts and no more than 4-6db above for the loudest parts. It's bouncing around, of course, so you're watching ballpark levels.
If the meter shows that the song is consistently below the 0 line, lower the threshold on Ozone's maximizer accordingly. If the meter shows it consistently 4 or more db above the line, raise Ozone's maximizer threshold. If the piece is extremely dynamic, it may even be necessary to automate the threshold in order to level out the overall volume.