As far as loading and updating map portions I found how pokemon rby handles this is by just drawing what in frame and only update the map it's on. I am planning on having a giant map but only updating and drawing 2 blocks surrounding the character so it wont lag or run slow.
I also created a catch formula based off of things I found online and made a function out of it, Id be more than happy to share.
Event triggers are going to be a tough thing, I am still working on the basics and haven't even started pondering different solutions, but I think creating something like an ActionEvent that allows an NPC to move. This might work well if you create a list that has a queue of many ActionEvents (move, display text, etc), then when talking to an NPC - allow them to either: Battle, display basic text, or execute a ActionEventList trigger...
I also implemented a dynamic text block displaying system that generates the right amount of border to display for a particular situation -- by simply generating 2 for loops width and height, for the size and repeating this throughout -- displaying blank blocks inside.
I'd be happy to share anything possible, the source code is available with every single release I put out.