I can't attest to CA vehicle equipment laws, but you're fortunate to have had a friendly encounter with two (!) officers who told you nothing else was of concern even though you were in violation by driving without a front bumper. Not many of us would be so lucky in any state. They either chose to ignore it or were surprisingly unfamiliar with vehicle equipment laws. I'm a former police officer (Ohio) and was, at the very least, obligated to provide some type of warning for a minor infraction. It's probable cause to stop and not worth the inconvenience.It is illegal in the state of CA to drive without a front bumper, however I'm familiar with law enforcement caring more about a front liscense plate attached to the vehicle. I have asked a few "PoPos" and it's to the officers discretion. I did get pulled over in Bel Air, CA because apparently it's a "thing" to commit crimes with paper plates. I had everything the officer asked for (liscense, registration, insurance) and no ticket. I asked if anything else was of concern (which I knew I didnt have fog lights or turn signals) and both officers said no. I took off my back bumper too! Rebel I know!!! I'll keep you posted if "no front bumper" or "no rear bumper" becomes ticketed
Anyways, as @BlackRook says, more power to you. When I swapped out my factory plastic bumper for steel, I was surprised at how much shiny stuff was exposed (this is my first Jeep). Without a front bumper, I'd be concerned about rear-ending a smaller vehicle, getting rear-ended, or having one back into me and damaging (or destroying) all those expensive shiny parts. Of course we do as we choose with our Jeeps, but running that risk ain't worth the vanity for me.