more deferred maintenance

I’ve been considering getting Mindful Mule’s rims replaced for a couple of years now. The sidewall on the rim is starting to get a little concave. I suppose this is from the pressure and friction caused by the brake pads against the sidewall of the rim – especially old pads that have hardened. I have no idea how to lace a wheel. I’m not sure it’s even worth learning although it might be fun. Until I learn how to build my own wheels I could either get Steve at Open Road to rebuild them for me or I could buy a new wheelset altogether – given the age and condition of the hubs, this latter option might be worth it. I’ve put this off for a long time. I keep saying it’ll be fine, it might last another few years for all I know. I’ve heard (on the internet) that wheels can eventually come apart if this concaving is neglected for too long, but how long and how concave does the sidewall of the rim get before it splits and what happens if it splits when you’re riding? And maybe more importantly, if I do get a new wheelset should I get black or silver?