I really like weasle-like dude. It is picturesque and conjures up a type of put-down with its own flavor, not conveyed by sleaze-ball.
I am not aware that Viki issues show-specific directives. The rating system used for movies in many countries circumvents the raw language/graphic content issue. Shows made for non-cable TV have tighter standards due to the lack of control over the age of the viewing audience.
However you want to tackle this or any issue as a Subtitler or Editor, there will always be complaints from viewers. Exercise reasonable restraint where it seems appropriate. Discuss it with your team if you need to.
Having said that, I agree with the comment above...if a viewer finds language, graphics, or subject matter personally offensive, watch something else that is in your comfort zone. The visual arts is not one size fits all, nor should it be.