Regarding Kri U'ktiv, see Radak on Shmuel II 15:21 who writes that during the first exile many serforim were lost, scholars were moved from place to place etc and as such when the Anshei Knesset Hagdolah needed to reestablish the tradition they usually went with the majority opinion. However, in instances where there still remained a lack of certainty the Anshei Knesset Hagdolah recorded both versions as kri u'ktiv and chose to vocalize one of them. The Radak does not seem to hold that the kri is more authoritative than the ktiv or vice versa.
Tzvi Daum
[
torahskills.org]
[
twitter.com]
