Based on my research the data available through the Linked API is very limited [1]. Basically `r_liteprofile` (name and photo), `r_emailaddress` (email) and `w_member_social` (post on a user's behalf). You can't get the users "vanity" url, profile information or posts. I'd love to be proven wrong though!
Many of us have already put in the effort to keep our LI profiles up to date.