Hi,
Any suggestions considering usage of quotation marks to emphasize gestures in action lines? Reading screenplays, I see them everywhere:

Ellis quickly ducks and mouths the word "shit."

Ron nods "it's ok".

Eve shoots him a “nice try” look.

Ron whispers a heartfelt, "thank you."

WHIP offers a “thumbs up” gesture.

Luttrell shoots him a look - “shut the fuck up”

She gives Jake a private stare that says, “stop or I’ll kill you.”

The Doc gives her a wink and a “thumbs up” and keeps on walking.

So, I guess they are okay in a spec script?

Yes they are fine.

Personally, I don't think half of them are needed and think all the quoting would be tedious to read. Occassionally , yeah fine, otherwise just write it without.

They read fine to me but something you could over do.

However, clarity in a script is key and if you have an important message to convey - say a change in reaction, or relationship and therefore a change in tone, or circumstance - then I would use them to not lose the reader. But it would be occasional.