How about these?
A shliach tzibbur who says “ga’al yisrael” in an undertone. It shoud be recited out loud.
I’ve seen too many people daven for the amud and not say the whole “Modim” out loud. Same for “Mogain Avos” on Friday night.
Blockhead-
You’re way off base in terms of nusach. MOST people correctly use the nusach of Shabbos Mincha for Avos as well. The kaddish before S”E Friday night is not at all like the kaddish before Barchu on Shabbos morning.
The only thing you are correct about is Avos on RH. It raises my BP when a guy starts doing Avos by Mincha on R”H (or Y”K) like the Avos for Shachris and Mussaf (which, btw, most people are clueless as to the proper nusach. Unfortunately, nussach is a dying art and I shudder to think of how the next generation will sound on R”H and Y”K).
As the gabbai in my minyan, if you are ever in my neighborhood and I ask if you are a ba’al tefilah, please say “no”.