I thought
Luiseach was pronounced LEE-sak, but I've never heard of anyone with that name, nor heard any authority pronounce it. Like an Irish person. :) I'd imagine, like a lot of Irish names, the pronunciation can vary based on where you're from.
Are you pronouncing
Lucia LOO-see-ə or LOO-shə? I'd pronounce it the latter, and I prefer that pronunciation. I'm generally not a fan for altering spelling for aesthetics. I'd stick to
Lucia, but Lusea doesn't look terrible. Have you considered
Louisa?
I like
Lucy, but not really any longer
Luc- names.
Luiseach looks cool (because I like Irish names), but I don't like the sound of it.