If its a 75B, then I'm betting it came with a 17lb recoil spring. You can take it down to 13lbs and it will function perfectly. As for the main hammer spring, thats starts as a 13lb, and I took it down to 11lbs. Changing these springs made a world of difference. This could also take care of your FTE problem since there is more rearward force, which will send the shells-a-flyin'. The CZ line is made for 124grn NATO ammo, which has a slightly higher powder charge, I'm betting you had no FTE while shooting the 124 grn.
As for racking the slide with weak hands or arthritis, try this:
1. Hold the pistol in the hand you fire it with. For example, your right hand.
2. Bring the pistol in front of your stomach, with it pointing toward your left arm.
3. Place your left hand at the rear of the slide, and your forearm on top of the slide.
4. Push forward with your right hand until the slide is fully to the rear, now you can procede in 2 different methods
4a. Raise your forearm and release the slide quickly.(if loaded, this will chamber a round, point in safe direction)
4b. Press the slide release upward to catch the slide. You can now insert a mag and release the slide at your leisure via the slide release.
Be sure to practice this with an unloaded weapon before loading.