You can use "like there has never been " of "like there has not been". The first sounds better. Using "as there" sounds funny to me.

You are asking if something can be done now or in the future. This doesn't mean past tense. Past tense would be "What if there were something we could have done about it."

Instead of saying " the way she is to my sister Melina" , it would make more sense to say " the way she did with my sister Melina." The first sentence was grammatically correct, but the way Ms.Mei started her sentence sounds better, in my opinion.

I am curious whether, besides the Guardian, there are any other UK newspapers worth reading.

I would use number 1, but they could all work.

This sentence doesn't make sense in English.

From the way it is written, I would think that "tapping in" is the usual way that supervisors give breaks. The tapping in may be literal meaning that they tap the person or do something that is counterproductive to social distancing. I would translate it to "Supervisors verbalmente tienen que permitir los descansos en vez de dar por "tapping in" y matenerse la distancia apropriada. Spanish is the language I am learning so this may not be perfect, but I believe it should give you starting point.

They do not sound natural. You could say: "Were you being sincere when you said [what they said]? "Were you being frank when you said [what they said]?