Thank you so much for the help (and for this great game)! I'm still a little confused on some of proper nouns and adjectives. I understand that Chihuahua uses is Wiktionary. Nevertheless, I cannot get certain word accepted that may generally be proper nouns and commonly capitalized, but they are also listed in Wiktionary as separate, uncapitalized words. For example, I tried playing "cypriot." I realize it's generally a proper noun that is capitalized, but Wiktionary has two listings: one is "Cypriot" (capitalized & referring to someone from Cyprus); the other is "cypriot" (no capitalization, listed as a noun with the same definition).
I try to use the general rule you suggested and have found it very helpful, but there are times I'm just not sure, and even if I check the Wiktionary after I've found the word, I am frequently told that what I submitted is not a word. The same rule does not appear to apply to words that tend to refer to a population; Wiktionary typically lists both capitalized and non-capitalized versions. I believe this is because some adjectives that were originally capitalized have now lost their capitalization because of current convention, but the most standard way I have been acquainted with as an editor was that proper adjectives that refer to where something comes from/religions/etc. (or that refer to a proper noun) are also capitalized.
I asked previously about "Latin"/"latin" and "Latino/latino." Both the proper noun and adjective there are typically capitalized. However, "latin" (lowercase) it is also the a singular form of of "lati" or "latu," the currency used by Latvia until 2014. Sometimes, the puzzle will accept French, Latin, or other non-English words that we have borrowed and/or now use in English. For example, "juste" was accepted today when I tried it, even though it is not accepted as a word by Scrabble/Merriam Webster. Wiktionary does list it, but only as a word that appears to be accepted if it is used in French or Esperanto. I sometimes hesitate to try certain fairly commonly-used words that have become part of our lexicon but originate elsewhere or, technically speaking, are not English words. When I try that, I get mixed results (usually not accepted).
My last question is about compound words (that may or may not have required/require hyphenation or been distinct words at times). I was allowed to play "bartender," but not "barback," which is a commonly accepted word and is not hyphenated or treated as two words by Wiktionary. I can sometimes play words like this, and sometimes I can't. I assumed that if a word requires a hyphen, it's not accepted because it isn't spelled without one, but some of these others are a little confusing. Any additional information is greatly appreciated, and thank you again! This is my favorite word game.