A cool idea
A melee healer is something we hopefully get some day. I really like that.
The parasites sound like fairy / sage buff as it is healing over time and seems to be persistent? Would it heal the lowest party member or a specific one?
Should this job be a shield healer or a pure healer? Since the other 2 HoT are shields, this one should be a pure healer... or something new.
The "atypical three move chain combo" would be a first for healers ^^
I hope the devs read your post and actually make something close to it