"Saving your reverence" was specifically an apology for using taboo language in front of a high-ranking priest, and the other similar forms were for using such language in front of some other person who might be supposed to be especially offended. I recall it being used in novels from the 1920s, and put in the mouth of a character with rather old-fashioned speech even there. I don't recall any more recent use.
The phrase "present company excepted" is an apology for saying something negative that might apply to someone present. For example, if someone said 'It is well known that most people named David are lazy" and then looked around and noticed that I was present, that person might say "present company excepted."
"pardon my French" means "I just used unacceptable language, but please don't be offended". I advise against ever using it, for several reasons. First of all, anyone who is in fact French, or has a french heritage, may well be offended. Send, it is a cliche, and rather tired. Third, and most important, if you feel a need to apologize for using the language, don't use it. If you think it is really acceptable, there should be no need to apologize for it.
I recall a column/essay from Judith Martin, writing as "Miss Manners", back in the 1990s, making that third point. She advised that a person should decide whether or not it was OK to use "shocking" or profane language in a particular circumstance, but if it was, no apology should be needed. But the "Apologize then use" routine only calls attention to the situation, and indicates that the speaker isn't really comfortable with the language either. I agree.