1. For our purposes, they are more like objects; however, if you would like her to continue seeing them, it would be no problem if a few of the mannequins absorbed enough of an individual's "soul" to count as a person. In other words, she won't see all of the mannequins but the ones most fully assimilated can show up.

2. The character will not! The pain only occurs once that full connection is made. Pre-assimilation, harming the mannequin will simply cause them to continue to pop back up, undeterred. They will bear the marks of being burned but can't be rid of.