Hi mate,
Leadcore's like marmite you either love it or hate it. I love it. Leadcore does'nt kill carp it's bad angler's that do.
As for your choice of rig's there any many options out there for you, Personnely my favourite's the Chod or the hinged Chod for popups, but it's how you mount them to make it safe to use. I think by far the best option is to use the helicopter setup with any choice of rig.
Altough at the end of the day there is no choice of setup that is 100% safe. But as you gain exspirence and by listening and learning from others its less likely you make the wrong choices.
I dont mean to be a bore. I hope it helps. Tight Lines