Nah man. If you care about your CDs you should already have them ripped to flac format, so the disc rot can't kill them. Convert to mp3 vbr0 for tossing them on a player or your phone. Listen with whatever ear buds you like.
It's not like vinyl or casette tape, where the analog nature of the storage medium is going to effect the sound. CDs are pure digital, just a carrying case for the files on them.
I agree about ripping the CDs to files, but disc rot is not a big deal to worry about if you're storing the CDs properly away from sunlight and heat. Recently I've been going through my collection and ripping old CDs of stuff I didn't have in the digital library... and all my CDs from the 90s that I've tried are still good. Many of these are 30+ years old and still sound perfect
wav is uncompressed PCM usually, flac is compressed and as such smaller (difference in size depending on the kind of music), but they're both lossless with the resulting signal being bit for bit identical to the data on the CD.
320 kbps MP3 makes little sense nowadays except for when you need maximum quality for a device supporting nothing else. For long term storage, use flac.
There's no technical reason for 320 CBR but the space loss from a VBR ~224 encode to the CBR 320 is minimal compared to 320 vs flac around 1000. I do keep two copies of my collection for space reasons though - one in flac and one at 320. My phone is still a limiting factor to from a space perspective, I can't store my entire collection on it in flac but I do choose to use it where I'm actively listening to an album through the weeks. The rest can be mp3 because it's usually a single song that gets in my head.
I don't really have MP3-only use cases anymore, but back when I did, it was mostly where transparency was achieved rather easily, like listening to music on the go with... non-perfect headphones, and on those cases, I went with lame's -V5 IIRC which is closer to 130 kbit/s or so. For higher quality, but not lossless (storage was still expensive back then) I used Musepack. But high bitrate MP3 was almost never needed.