I have not owned a revolver in around 30 yrs. I just bought a M 327. Is it safe to carry with 6 rounds loaded, or do you need to carry with hammer down on a empty cylinder like the old revolvers ? Also do you need snap caps to dry fire ?
Your new revolver will have a transfer bar which prohibits the hammer from striking the firing pin unless the trigger is pulled, accidently dropping the weapon will not cause it to discharge. So the answer to your first question is you can load every chamber without problem... load it full.
You can cause damage to the firing pin by dry firing. You need a snap cap or other devise (spent brass) if you're going to dry fire the gun.
Just take 6 empty cases and knock out the primer. Put a dab of silicone in the primer pocket. Once dry, use a razor blade and trim it off flush with the case. Homemade snap caps. I would load them up and dry fire a couple thousand times. Especially in DA. This will build strength and muscle memory and help you work on your sight picture.
Then put in a wolf hammer spring and the DA pull will be much lighter and smoother. Right now my 327 has a stiffer DA pull than my TCP. If you change the hammer spring, make sure you test fire it. My gun didn't seem to like the lightened hammer spring, and I kept getting light strikes with no ignition. I ended up putting the factory spring back in.