In a decocker the safety is the trigger... but it is a long and deliberate pull... no accidental pulling there... and it has a firing pin block so the only way the firing pin hits the primer is if you pull the trigger.
I would pick a 45 over a 9mm if I was restricted to FMJ rounds only. Both will over penetrate with FMJ.
Some find the CZ 97 to be too large in the grip. Recoil should be mild due to the design and weight.
1911s are not something I recommend for new shooters... more so if they want to use it in a defense role... They can be temperamental, and need some tweaking to run 100%... This gets more likely as the price lowers. Good pistols, but they have been pulled out of their comfort zone since the original design... I want one sometime, owned one a few years back, commanders in 40.