How would you go about intentionally pissing off your god then? In emergency situations, being able to curse an item or destroy your equipped items can be of value.

I also use this for self-dooming challenges...

I kind of like the idea of having a holy symbol equipped block (or at least reduce, depending on B/U/C status) the unanswered prayer penalty though.

Didn't you watch Bruce Allmighty? :) Unanswered prayers do annoy the god hence it makes a lot of sense for them to reduce piety.

I'd do something to actually receive some help from the god.
I don't know what exactly - and that's the main reason for this RFE, as outside emergency healing and (pre)crowning I'm seriously unfamiliar with other miscellaneous things prayer can do, as experimenting is too expensive even if I don't receive any benefits.

Maybe you can do something like pray on some of the statues?
Or pray to detect hidden doors?
Or get something interesting for praying after entering a special message room?
There are myriads of other potential prayers that no one has ever discovered since they are so obscure and rare. Wiki and guidebooks are not supposed to be the main source of player's information! They should serve to help you refresh your memory, but not to spoil you.

What if you pray and nothing happens, but an under-the-hood timer starts. If you pray again within 50 turns(also for no effect) your god starts getting annoyed that you keep bothering him.

So if you *want* to annoy your god - just keep on praying.
But if you just want to try something, you can experiment occasionally.

"Nothing happens"
"Nothing happens - but you feel your deity is displeased with you for asking so often"