Don't worry about it unless you have reason to believe it's worn out. A properly setup Jeep can run fine without a steering stabilizer, so you'll be fine unless it's shot.
I would replace it. Personally I swaped mine for a new heavy duty one. It made all the difference in the world. The stock one is the equivalent of a screen door shock in my opinion . But it's up to you
I found it cut down on the shimming that occurs when going over railroad tracks and pot holes
Make sure you take color into account when ordering the new one. It seems that manufacturers love to make these things out of florescent colors. I think Rubicon Express, Rough Country and possibly Teraflex are all silver / black
Same as bounty mentioned, you really don't need it. In my opinion, I find that a stabilizer will mask and hide actual steering feed back issues like bad ball joint, improper toe etc..
I agree %100 with Bounty and JPS. They are not needed at all if your alignment is set correctly. If not they just cover up symptoms you should be noticing so a small repair doesn't become a big one.
I run tires as large as 41x14.5x17 and I do not need one at all.