I just love how this revenge manga takes the form of an active "the best revenge is living well".
As in, she is not just overfocusing on revenge and tricking everyone.
She is not just doing what she (or Emi) would like and letting the other side explode by itself.
She is focusing on a revenge that does do what Emi would have wanted, in a way that explodes the other side and no one else suffers. She is doing it all for revenge, but in a way everyone but her targets end up happy.
She is helping people left and right both because Emi would, and to help everyone, but also because, without conflicts big enough, Pina can't go out and become stronger and more influential.
The potions store, regardless of her actions, if she pointed the guards to it or if her words are even true, is definitely in-character for Pina. She did claim Pina's overuse of charm potions drew unwanted attention, and I can see those she did not influence yet seeing things wrong sooner or later. And we know she is getting desperate for those potions now that she can't get any more.
And of course, even while stopping Pina from progressing through the story she is doing it herself.
Getting the special equipment, and fighting solo against two gods (well, she planned the second to be solo) to end up the threat to the world. Plus she is even stopping the demonic invasion threat before it even happens.
If she succeeds, everyone else ends up the better. The threat is gone. Or did not even start existing.
Save for the Miasma, which regardless of everything it seems only Pina can clean up.
Meaning that, in the end, Remilia becomes adored for her actions of helping everyone, Emi hopefully ends up happy when she wakes up...
And Pina's special status is made to be only the "official janitor to the world".
(No offense to real janitors, it is a thankless task.)