I found out Mukhtuk is from Nivkh мухтук "mouse"
https://ru.m.wiktionary.org/wiki/%D0%BC%D1%83%D1%85%D1%82%D1%83%D0%BAhttps://glosbe.com/niv/ru/%D0%BC%D1%83%D1%85%D1%82%D1%83%D0%BACouldn't find anything to support the whale blubber claim
For Stettin I did find the thing about Szczecin so it might be a German surname denoting to a person from Szczecin in modern Poland, since in history Germany and Poland (or parts of the two) were in the same country a lot.
For Romius, yeah I also thought that. I'll list it as a theory.
For Gekko, I found that it does indeed mean moonlight in Japanese.
https://en.m.wiktionary.org/wiki/%E6%9C%88%E5%85%89#Japanesehttps://glosbe.com/en/ja/moonlightForebears finds a few bearers (surname and forename: linking both because it tends to mix up the two in surname forename countries)
https://forebears.io/x/forenames/gekkohttps://forebears.io/surnames/gekko
For Sanet- source that it's a diminutive?
For Larinson, most of that information we already knew.
For Bestock, I think it's actually from a Slavic last name, though I have no source for this statement and could be wrong.
For Lyions- source?
For Gaydarzhi, noted.
For Korea, that doesn't really give me any actual information.
For Bolerjack- source?
For Freiwat- I know that "frei, freie" means "free (as in freedom)" in German because of the FDJ. German-Danish translator says the Danish word is "frit".
Do you have any source that it means that in Danish?
https://translate.yandex.com/en/?source_lang=de&target_lang=da&text=freiFor the wat or vat part of the name, things I found it meant in Germanic langauges:
Cotton wool (vat in Danish):
https://en.m.wiktionary.org/wiki/vat#DanishWhat (wat in older languages or modern regional colloquial):
https://en.m.wiktionary.org/wiki/watWalking through water (wat in German, grammatical form of waten):
https://de.m.wiktionary.org/wiki/watDanish Wiktionary doesn't
find anything on vat:
https://da.m.wiktionary.org/w/index.php?search=vat&title=Speciel%3AS%C3%B8gning&ns0=1What's your source for the Old Norse meaning since I couldn't find anything?