then there will be nothing stopping/that stops us .... "If we can master distraction, then there will be nothing stopping us from reaching our goals." "If we can master distraction, then there will be nothing that stops us from reaching our goals." The first one is from an article and the other is the modified version. Are they different in meaning? Which one is more natural?

"How do you know [that] what you...." "How do you know that what you know is true?" "How do you know that what you're buying is even safe?" "How do you know that what you create is truly yours and not influenced by others?" Could we leave out "that"? Is it common to see "that" placed before "what" like this?

Is "by" omitted in this sentence? "The first thousand people to sign up using the link in the description will get their first two months free." This is a sentence from a sponsored Youtube video. I saw it and wrote it down. I think the full sentence would be "The first thousand people to sign up BY using the link in the description will get their first two months free."

"You will lose your life staying here longer" I'm writing a short story and here is the brief context: The protagonist is in a very dangerous place but he doesn't know about it. A crippled old man sees him and tries to tell him that he will most likely get killed if he stays here longer. I want the crippled old man's line to be "You will lose your life staying here longer" but is it grammatically correct?

"I've had enough trouble dealing with you" Could it be explained as "I've had enough trouble WHILE dealing with you" or "I've had enough trouble IN dealing with you"?

"I know American culture very well living there for ten years" If no context is given, can all these variations below be considered as the likely meanings for the sentence? "I know American culture very well because I HAVE BEEN LIVING there for ten years" "I know American culture very well because I HAVE LIVED there for ten years" "I know American culture very well because I LIVED there for ten years" "I know American culture very well BY living there for ten years"

Grammar questions about "What do we have left?" Can it be considered as a shorter form of "What do we have which/that has left?" But then I think it could also be "What do we have which/that HAVE left", what do you think? --- My question is, can we see "left" as a reduced relative clause? Which relative clause would it be?

It has been great [talking to you]/[to talk to you] If we just finished a conversation with someone, which one would be a better pick? And why?

There has been done a lot of/some changes to something Is this kind of sentence grammatical and natural? If it is, can you show me more similar examples? Thanks.