Welcome, @DarkBlastoise27;, good to have you around.
Gosh, great answers! I never think of the more symbolic hints immediately, and I wind up hitting my head in why didn't I, haha. I am fond of the whole Ash commenting on her guiding him through reminisce there, yes. Time for my answer:
What flashbacks (in relation to Pokeshipping) would you like to see and what would you like Ash's reaction in BW to them to be?
I wouldn't mind Ash recalling his ghost lifting her into the air in The Tower of Terror, and commenting lightly how fun she was to tease.