Final Final Version[tm]. My past regex was shit.
Regex: /,(?! (?:and|or|but))(?!.*\b(?:I|you|he|she|it|we|they|one)\b)[^,\n]*a (?:mix|mixture|blend) of (?:(?:(?:[\w ]*,? )*and [\w ]*|[\w ]*))(?:([^\s\w,:])|,)|a (?:mix|mixture|blend) of (\w*)/g
Replace with: $1$2
Nukes most junk dependent clauses containing "mix of", and simply removes "mix of" from most independent clauses.
If you want to, for the beginning of sentences you can add /A (mix|mixture|blend) of/g
then manually capitalize the word after it.