とでも is not a word by itself, but two particles in a sequence:
It’s hard to give any detailed explanation without context, but it’s most likely on the lines of “even if one is at the same level of a god”
EDIT: Are the characters mentioning what someone else said about one being at the same level of a god? (The English translation you provided also indicates that by using “deeming”) If that is the case, と is most likely being used as a short version of と言う or と思う, so the full sentence would be 神と同列とでも言う
About それにしては, I would say it is a bit closer to “considering that”, but it is hard to get a clear-cut English translation. Japanese sources also say that whatever comes after it should contradict the expectations of the first sentence.
It’s pretty quiet, considering they say a Typhoon is coming.
Be aware that when used towards people it can have a bit of a condescending nuance.