First of all, you should never really have to "prune" an Echeveria. It looks like some time in it's past, it was receiving really low light levels. From the looks of the current rosettes, I would say it is in better light, but still needs to be beheaded.

By the way, cutting off the heads wouldn't kill the plant, as more rosettes would probably come out of the sides.

I would say behead a few of those nice looking rosettes, and put those in DRY soil, to wait for them to root. If they don't root, it's not a big deal (as said in above paragraph). I really don't know what you should do with the rest of it, however.

Agree with palms - more light is needed. I would also be-head few branches and re-root as described. And perhaps do not worry about plant blooming yet, get it stronger with more light. The rosette at the bottom is another offset more likely growing from the stem as other are. I believe these grow into small 'shrub'.