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.
You have said that
"The Good Faith Rule for IvE will include the fact that in order to take a Favor action, you must either control the Favor or have another way of paying the cost of the discard of the Favor. So you cannot have Favor actions "Fail" to play the Ring of Air."
Even if I have the Favor, can I choose not to discard it and not gain the full effects of the action? (That would be because I want to keep it for another Favor action).
You have said that
"The Good Faith Rule for IvE will include the fact that in order to take a Favor action, you must either control the Favor or have another way of paying the cost of the discard of the Favor. So you cannot have Favor actions "Fail" to play the Ring of Air."
Even if I have the Favor, can I choose not to discard it and not gain the full effects of the action? (That would be because I want to keep it for another Favor action).
No.
Discarding the favor is an effect of the Favor actions. You can't choose not to discard the Favor if you have it, just as you can't choose not to bow your target unbowed Personality if you play Unassailable Defense.