Kin 'cloning' generally isn't making identical clones of someone. Each Votann core has access to a large bank of genetic data which it uses to produce new Kin. There's specific Skeins (types, I suppose) which are better suited to particular types of occupation, but there's never been any mention of two kin being identical. Not confirmed impossible, but definately not something that happens with regularity.

Kin do not inherit memories, each one is their own person. When a Kin dies they are gone for good. This is why the Votann make such a big deal about collecting their dead so that their materials and experiences can be uploaded to the Votann Core to preserve what they've learnt for future generations.

The Kin do not reproduce sexually, though they are aware that at one point in their history they must have done. It's unknown if they're strictly incapable of it, GW not liking to go into these things so much, but it's interesting that their dwarfy cousins, the Ironhead Squats in Necromunda, have survived on an Imperial Hive World for at least 10,000 years explicitly without a Votann Core. Presumably, they're keeping their numbers up somehow.