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.
Two questions.
1. If my opponent plays Lakeside Retreat but has nobody bowed and I do, wouldn't Lakeside force him to straighten my personality or follower?
2. If I Calv a unit into a battlefield and then attach a non-calv follower does that now make the Unit a non-cavalry unit and thus eligible for protection from Temple Grounds?
Two questions.
1. If my opponent plays Lakeside Retreat but has nobody bowed and I do, wouldn't Lakeside force him to straighten my personality or follower?
2. If I Calv a unit into a battlefield and then attach a non-calv follower does that now make the Unit a non-cavalry unit and thus eligible for protection from Temple Grounds?
1) No. The Terrain's trait doesn't specify that a bowed card need be chosen. He could choose to straighten one of his Personalities or Followers that is already unbowed, and have the straightening simply fail.
2) Your question seems to be making some assumptions about the game state that aren't explicitly delineated in what you wrote, but I'll try to ignore those and answer as plainly as possible:
If you have a Cavalry unit at a battlefield and, during the battle, attach a non-Cavalry Follower to it, then it is no longer a Cavalry unit while that Follower remains attached. So, after you do that, if you have Temple Grounds in play at such a battlefield, and the other player controls no units there, his Battle actions WOULD be negated by Temple Grounds' trait.