The safety on the 527 works perfectly. I doubt that it could be changed out and would wonder why. We use all different kind of safety's, from the push/pull of the old Ruger 77 and modern Mossberg shotguns to the three position of the Winchester to the trigger guard button of the Remington shotguns to the push lever of the M-14. All are different and all work. I've used this CZ safety now for over two years on a 452 22 long rifle and for the last six months on a 527 with absolutely no problems.
The question is can you learn to use a different type of safety than the Remington 700 type? I'd bet using it for a while would make it as easy to use as any of the safety's mentioned above. It was for me and I own rifles and shotguns with several different safety's.
Ah for the trigger. The little CZ single set trigger can be adjusted to have no creep and no over travel and break at most poundages from about 1.5 and up. The set part can be adjusted in the ounce range and is extremely easy to use. Why in the world would you want an after market trigger that in all probability would be no better.
If after handling one of these fine little rifles it does not feel like it would be comfortable to handle for you I'd suggest looking at a rifle you would feel comfortable with. There are a bunch of really fine rifles on the market right now from Remington, Ruger and Savage just for beginners, though all three have different safety's that require getting used to.