I feel like the name "mullivad" might present challenges for user adoption.
Totally agree. Everything should be Americanized as much as possible so that it conforms to American sensibilities and is easier to use and understand for Americans.
Who cares about languages and culture of few dozen people who does not live in AMERICA.
Am I (native Swedish speaker, so perhaps ignorant of secondary connotations here) missing something that should be obvious? Is mullvad inappropriate to some readers or is it just an odd name?
No, I don't think you are missing anything. As an English speaking American, it just strikes me as a strange name that I wouldn't immediately associate with a search engine. Note for example that the parent spelled it wrong despite that being the focus of his question. But there is no second level of meaning or innuendo that I'm seeing.
current options are google, duckduckgo, bing, I think they'll be fine; what's in a name? and all that