Does anyone know, if it's possible to change aiming from holding right mouse button to clicking once. One click to aiming on and one click aiming off.

Couldn't find any option for it, but perhaps it would be possible with some config editing etc.

Bump

I'm pretty sure that option is unavailable in New Vegas.

Anyone knows?

Just sounds quite weird if you really couldn't change that. I mean, there's fix for changing camera view, mods etc. For example Borderlands had the same situation, but with certain line and fix to config changed that option.