Yes
I don't know if you have one and are thinking of carrying it, or if you're trying to decide whether or not to buy one. In either case, I can tell you from personal experience that the Px4 carries just fine. I wear mine Every Single Day. If I'm not at work, in bed, or in the shower, I'm carrying a Px4.
To address your points:
-There are not "smaller grips," per se. They come from the factory with three
backstraps, in small, medium, and large, and they serve ONLY to adjust the feel of the gun in your hand. I assure you that you will have no problems whatsoever with concealment based on what backstrap option you select. So go with the one that feels good.
-The exposed hammer is not of the spur persuasion. It is more of a rounded combat type, so the likelyhood of a snag is greatly reduced. You won't be coming out of a pocket with this gun, so you'd have to clear a concealing garment out of the way of your draw somehow anyway.
-Shooting oneself in the leg is a scenario that will ALWAYS (read: Every. Single. Time.) be prevented by observing
The Four Rules of Gun Safety. No modern firearm in working order handled safely (a la
Four Rules) will shoot you in the leg. Unless you point it at your leg and pull the trigger with a bullet in the chamber, of course.
All that being said, it's only fair to warn you that this pistol is still relatively new. That doesn't mean anything bad about the gun itself, but accessories can be tough to acquire. Particularly holsters. If this is the gun you want, be prepared to search high and low for leather, and to wait for it.
My holster took me about five months to arrive, but MAN was it worth it!!! For custom leather, that's the case with just about any gun, but no one I can find makes any regularly stocking item for the Px4.
I hope that helps. Oh, and if you DO go with the High Noon Holster in the link, be aware that they make the holster for the 9mm and .40. They have not specifically mention the .45 model, WHICH IS SLIGHTLY LARGER!
Enjoy!