Don't know if there are any special techniques for rooting these. Maybe just time. You might try cutting off some of the dried up bits at the very base to expose fresh tissue, but that might do more harm than good. Depends how desperate you get during this year, I supposed.

I leave my handful of Echeverias dry over the winter. They are variously cold or frozen. The only losses in an unheated greenhouse have been from botryitis on E. setosa rather than the cold, which I suspect was too damp going into out usual dull humid autumn. There may be some species that are less ...

Yup, read the journal. It describes, and shows, how the plates expand from green live material deep down between the plates. You might just have a case of that. Perhaps see if you can shine a light down and make sure there is something still in there.

Quite slow. Most of the growth below ground. Otherwise not too difficult. Probably prone to scorch without food ventilation, but I haven't had any problems with them. Watch out for mites.

Seems like a good time to separate them. Or you could water. So long as the oldest leaves are getting softer, you're doing fine.

You can never have enough Lithops

Definitely getting bigger!

Not sen the pink one before. Here's the more typical colour. These are well worth looking at magnified, very intricate patterns and windowing.

Treat them more like Lithops than Conophytums, but don't be too strict about withholding water until the old leaves are gone. Pleiospilos are somewhat opportunistic growers, with P. nelii the most inclined to grow in cooler weather but they'll all grow in summer (in the UK) provided it isn't too hot...

Same here, no flowers on mine yet. My older and much more purple plants flower, but not prolifically.