Yes but the end result is a little different for each sentence. "Let's end it now" is better than here, but people do say here. = something like şimdi birak ve dur "let's leave it now/here" = only stop leave it for now= something like şu anda birak ve bir sure Leave it is not the best way to end a violent or viscous quarrel it is usually stopped/ended with a stronger word like "end it" leave it may be used for a minor quarrel.

yes both are fine but of course they have different meanings the first one means sth has to end and the latter means sth is not going to be finished now and here instead it is going to be postponed and be dealt with later. hope I could help