I really have no idea if rings are harder or not, I've heard opinions both ways. I used to do straight bar stuff, took an eternity off due to an elbow, and do rings now. I'm at about the same volume/sets and don't have any interest in hitting a straight bar for comparison. (To be fair what got my elbow was a combo of chins and bad low bar squat form, but still not worth it). Even if they are harder it's no big deal, just drop the reps to whatever you need to and keep building.
On the topic of neutral grip in other stuff, yeah in most cases it's going to be more joint friendly there too, but harder to get totally away from straight bars as it's sort of the core of everything. I just do DB rows so I can keep a neutral grip, but use a straight bar for presses and deadlift, then a SSB for squats to save the elbow/shoulder. If joint health is a concern I've heard of people going to swiss bars and the like for supplemental work but keeping the main lifts going on straight bars, once I can swing a swiss bar I'm thinking of trying this.
Good luck, it's great you're thinking about this BEFORE you have an issue, good spot to be.