I carried unchambered when I first started carrying (G19 BTW) and nothing ever caused the triggered to be accidentally pulled. Also, since it wasn't chambered, I was never cautious in any way when I holstered it or any activity that I performed while it was holstered.
Then one day I just racked that puppy and have been carrying one in the pipe ever since.
Personally I think if you have any doubts, you should just carry unchambered until you prove to yourself that it's safe. At least for me, there was no other option. There's not a person in the world that would have changed my mind into carrying chambered from day one...Lack of my experience/confidence.
Old Enough To Know Better...Young Enough To Do It Anyway.