This is a fun way to meet, pretty darn handy.
Nice! I love it when there is that energetic confirmation. Continue to be guided by your own inner compass as well! Nice work!
1. I think the size of that rose quartz gemstone should suffice. It does sound like it would be on the larger side but I believe large earth would be more of a boulder or terra cotta pot.
2. Yes, it is enough to do the activations in one area in order to suffice for that entire segment of the bagua.
Imagine the effect of standing water on metal. Think of an old bucket sitting in the garden rusting away with the standing water inside. That is how the still water weakens the metal element whereas moving water wouldn't be around long enough, figurtively speaking to cause the weakening of the metal.
All the best!
Kat
