For the cultures, I found some spelling mistakes and changed up some of the base names, like using _Calixtus rather than _Callisto for the base name. I think using the Anglisized Latin versions of these names makes it easier to use as a base, like _Justin rather than _Iustinus.
I've added translations for some Italian names you missed like Giulio/Giolio_Julius, Giovanni_John, Giordano_Jordan, just to name a few. Fixed some misspellings here and there and capitalized some names as well.
Also added Jules, Constantin, and Justin to the French list. All translated.
Translated the name "Ademar" for French, Occitan, and Portuguese cultures.
Added the name "Orso" to the Italian list, translated to Ursus as a base. Lombards have the name Ursus which can translate well since they flip to Italian.
Added "Peter" to the Lombard name list, mainly due to many Lombards in 769 are named Peter (originally not in the list) rather than Petrus(in this list by default and translated), which messes up regnal numbering unless the history files are changed.
Added translation for the Suebi name Vermund_Vermudo.
I have not added any new cultures you've posted, so when you post the update, put yours in there. If I missed a fix let me know.
EDIT: Also edit the localization file. The empress title translation for Italian is not capitalized. I fixed it on my end but since the file is an excel file, I can't upload it here.