We have text readers already in game for a variety of things. Whenever a word shows up in the text, it triggers a result within something else.
I think it could be cool if there was a visual effect that occurred when you spoke the name of a deity. For example, if you worship Shar, and you speak her name, maybe there would be some visual cue of her hearing that name spoken. I know that's kinda what the cleric is for, however...
It means that if someone "unworthy" or of an opposite alignment speaks a deities name that is extremely powerful... perhaps they get stricken with something. Just a thought, others can embellish to tear it down as needed.
I like this idea, but I think it should be a rare probability role. The probability increasing depending on the deity. Shar probably wouldn't be one to strike someone down. Now, however, if you were to utter Orcus's name you would likely have your heart ripped out or his Avatar manifest infront of you and drag you into the Abyss. Though it seems relatively taxing on an already overburdened DM staff. Maybe it could be enormously simplified as applying to the darker gods who respond badly to having their names uttered like Beshaba and Gruumsh, a hidden roll made, and if the circumstances are right; you're stricken with some sort of penalty for blasphemy.
Though the suggested mechanic is setting-wise possible, it is not setting-wise probable.
All deities already have the ability to know whenever their name is spoken, and instantly be aware of all goings on around the spot where this happened. There is no visual effect associated with this, though.
No. Setting canon has always been that Gods very, very rarely directly involve themselves, and if they do, it is always through some sort of divine servant.
Have you been drinking agien Ebok?