You're fine even if the app status is still showing as incomplete. Have a look at this blog post from the admissions team: http://hksadmissionblog.tumblr.com/post/181078275158/2019-application-reading-and-decision-process :
"Based upon our work in previous years, we will not certify some applications as complete until January. As has been stated in previous entries, the order in which files are certified as complete has no bearing upon the final admission decision."
Not sure about the GRE question, but my understanding is that with ETS/GRE you get to pick which score to send. So if you only chose 2017 scores, only those will be sent.