While 5% is not 10% - 5% is still a lot in an optimized build. Maybe you’ll find a perfect Cirri - it 's 10% again and you would regret i that you ruined a perfect item.
LpH - the build has already a lot from simplicities and shadowpower (plus indirect LpK gain). But I don’t now how often it procs here - if 4 pc works (piercing not) - that would already be ~6 LoH hits per second.
As Ballista is usually played with Squirts and used for speeds- LpH to Vit might actually help. You could also roll to AD or maybe elite Damage - since it is a primal you can easily change that. For primals it doesn’t matter what you roll actually - what matters only which slot you roll off.
I would roll LpH to X. For pushing with AD - I’d go with valla - but you can do this with ballista. Reroll it then to AD. Just remember that you can change primals easily.
Even if LpH is super nice for now - you can roll it off and then just pick it again