I have only briefly looked over it for now, but basically my wishlist aligns very closely with Overboy.
1. Being able to link an entire flowchart into the out of a node, or reference it somehow else. But I think linking would be the best probably (?)
2. Being able to enable/disable nodes based on some snippet of code. (If player has money, show "gamble" node)
3. Being able to execute a snippet of code whenever a node is reached. (Play sound whenever node is reached)
4. Being able to execute a snippet of code whenever a connection is traversed. (Remove 5 money whenever "gamble" is picked)
4b. Being able to branch a connection based on the result of a snippet of code (If gamble won, if gamble lost,...)
Nice to have
5. Aligning nodes etc. to a grid, I like grids :)
6. Every other row in the node could have a slightly darker/brighter color to make it easier to see the rows.
I think this would do a lot of heavy lifting and tie together the flowchart closely with the logic that's supposed to drive it. Right now it's all raw data and strings which all have to be handled in a quite detached manner in the eventsheet. If I think about a larger project, this sounds daunting to work with.
Quick mockup just cause. I think the "Eventsnippets" could theoretically just be a function in an Eventsheet, but I think it would be better if it were a mini-eventsheet as Overboy suggested.
EDIT
I think the fundamental problem with adding the functionality to execute logic to nodes is that the more logic capabilities flowcharts had, the more they would overlap with event sheets.
I can see what you mean but I feel like these suggestions were almost inevitable :) There has to be a way to create a sensible interface between the two. Purely thinking of a text-adventure as in the example, I'd totally want to do things like "If the player is low health, show/hide this option" and "If the player picks this option, there's a chance that X will happen". Right now this would seem like a lot of frankensteining together flowcharts at runtime, and my gut feeling does not like that.
For example, how'd you do a check for: "if (player.health < 10 && player.poisoned) showOption()". Currently a flowchart has two fields where we could convey this information we want to test for with the eventsheet. The name, and the value. The name doesn't really appear to be the right place for this. The value... maybe? But it would mean we have to write a JSON string into the value, then parse the JSON, then extract the intent what we want to check for with which values, call a function and if true, stitch in some flowchart. When with the other approach, we'd just have a field that says "condition" and we throw in a function that returns true or false, and if false the node is not shown.