Ah, I think you are right! It matches bell heather pretty well. Thanks!

any of the artemisias, I'd think- I have three or four, from one that looks much like 'dusty miller' to one that passes for cushion moss, it's that low and feathery. russian sage has silver/green foliage, and purpley flower spikes- but it's a sloppy little bushy thing, and can really take over.

That is sunburn. Normally Busy Lizzies don't burn easily, but if they become stressed from lack of water they may do. Do nothing except look after them better and they should recover. By the way resist the temptation to pull or cut off the damaged leaves as this might introduce fungus. They will drop off of their own accord. You might like to consider growing them in more shade in future. Good luck. Ian.

Thanks carol23_gw!!! That looks very much like my plant. I wouldn't have guessed Pothos, since my only familiarity with it is the Neon Pothos (and I almost bought that today as well!).