Bubba- there is no single CHL scenario. Frankly it is rather improbable that the majority of the people on this forum will even be involved in a self defense scenario that includes a firearm yet we carry one anyway. In addition by practicing clearing drills you gain a greater understanding of your firearm and its functions. I fail to see how that is a bad thing.
Lastly, y'all seem to only be considering about firearm malfunctions. I carry a very good firearm and I do not expect it to malfunction (then again its a semi and springs do fail eventually). The same can be said of my ammunition. I carry Federal JHP and as far as I am concerned those are high quality bullets. However no manufacturing process is perfect and if one of those rounds is of poor quality Murphy's Law states that it will be the one in the chamber. So I suppose I should ask, Bubba how do I as the operator prevent that little incident from occurring? The answer is I can't.
OT- I usually carry an extra magazine if for no other reason than the BSA long ago instilled in me the idea to always Be Prepared. Which is why I also carry a cell phone, 2 knives, a multi-tool, and a first aid kit in my rucksack.