Regarding this ruling, if the Spell's trait doesn't specifically state "This Shugenja", such as Scouring Flood, will the Personality retain the bonus if they should lose the keyword?
Spell traits and non-Shugenja
A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
Regarding this ruling, if the Spell's trait doesn't specifically state "This Shugenja", such as Scouring Flood, will the Personality retain the bonus if they should lose the keyword?
You are correct, the wording on Scouring Flood does not require the Shugenja keyword to give its force bonus.
On: Scouring Flood