It's near impossible to properly train MMA and not have irreversible damage
You are also 33, so if professional MMA isn't an aspiration, I would just pick one art and try to stick with it.
Not to sound harsh, but I don't think your view of how to approach it will work. For example, for you to be "decent" at BJJ, it would take you at least 3 times a week for at least 2 years. With the wear and tear on your body and with you wanting to dip in other disciplines, you'd have to be prepared to be the "nail" (at least in BJJ class I can tell you) for a long time. Meaning, you are likely the worst person in class and would constantly get smashed. Now imagine doing that for multiple arts, multiple times a week, it would be hard to sustain.
But definitely try things: I'd recommend figuring out if you prefer a striking art or a grappling art. Once you pick that path, then you can pick 1 art (Boxing, Muaythai for standup, or BJJ/Judo/Sambo for grapplin) and try to improve in that.
