Unwieldy lists of Primary Categories and now Parent Items

My site's a community service project and a soapbox for this retired community health center medical director. Anyway, the site's working after a fashion but the developers disabled the Categories module because the list of Primary Categories showing up on my home page was getting unwieldy. Now I see the same problem (growing lists) in Parent Items. Also I have no way to re-enable various items there (i.e., I cannot find the taxonomy list that showed me what's been disabled.