So the way that the Paraelemental Plane of Ooze is represented in the canon is that the whole place is just filled with a disgusting morass and it's inhospitable to life in the extreme. Pockets of acid and/or disease are scattered throughout the entire plane and any unlucky sods who find themselves in one of these pockets is liable to end up in the Dead Book right quick. Any native creatures or inhabitants on this plane are almost always hostile to outsiders. So, as far as establishing the overarching theme of the Inner Planes - survival - the Plane of Ooze plays to that theme quite well. As written, there's almost no reason to visit the place, which means it's ripe for renovation.
The thing is about Ooze is that it's filled with the stuff of life. All those mounds of offal and garbage and everything else under the sun that's just plain disgusting? It's everywhere in Ooze. And when that stuff all breaks down, it turns into the that that plants use to grow on. Dilute a sample of the stuff of Ooze and use it to fertilize a field of crops and you could almost watch them grow.
Given that in the Plane of Water you can find entire forests of kelp or other underwater plants or even islands of coral, there's no reason to believe that you wouldn't likewise find entire masses of ooze-adapted kelp, or colonies of fungus living in the morass. It's in and around those islands that you're going to find sentient beings who, against all odds (as per the usual standard in the Inner Planes), are able to eek out an existence in such a hostile location. I could see exotic farming communities growing immense plants that thrive on the nutrient rich environment. (Hehe...culinary delights from the Paraelemental Plane of Ooze!)
It's in that interplay between the Plane's tendency towards putrefying and decaying living materials into base components, and then resulting ooze giving way to the fertilizer that other things grow upon that's really the key to the Plane. Sort of a intra-planar Growth vs. Decay tension. At least it is in my mind.
I'd love to hear other folk's thoughts on the topic. I'll continue to pick at the idea as things occur to me.
In addition to a strong theme of Growth vs Decay present, I could see another undercurrent of Ugliness vs Beauty emerging from the plane. In the section about Ooze in the Guide to the Inner Planes (p. 85), it mentions that in certain deep pockets in the plane, pressures create pearl-like gems (quiila) that fetch a high price elsewhere. These are gems that just can't be found elsewhere in the multiverse.
I'm not quite sure how you'd go about expanding that idea elsewhere in Ooze though. But I thought I should capture the idea before it slipped away.