If you're a magic build, possibly nirn would be good on the weapons. On weapons, the "nerd math" still shows it slightly outperforming sharpened.

Sharpened is generally the second best dps trait. Just an all around minor buff.

Enchantments are up to you. For my v16 gear, I go unresistable damage. It's a little less than elemental damage, but...unresistable. In pvp, that means there's no CP that protects from it.

At times, I also go with resource returning (magic damage plus restores xxx stamina). It's not great, but I don't use my light and heavy attacks much. As a stamblade, a big percent of the time is when I have siphoning attacks active to get stamina back...this assumes Im in a tough fight, so resource management enchants help in those circumstances.