Let's face it, the entire eventing system is beyond obsolete and needs a total makeover. Not only is it unappealing to work with but it also discourages users to making huge evented contraptions and concepts that could potentially change Blockland. And I'm not talking just an aesthetic change or added small features here and there. Nothing that you add to its current stage will make it any better.
I was thinking that the layout should be more along the lines of "Block Coding", as shown below in the example of the scientific program called Labview, for the sake of simplicity and flexibility. Basically you have a palette of "blocks" to choose from that perform specific function, divided into categories much like the current system (inputs, targets, outputs), except including much more such as loops and mathematical functions. As shown below in this projectile formula program I made a long time ago, the wires that you see are data wires that transfer information from one block to the next. The different types are data are shown by the color of the wire (integers, booleans, etc).
Just think about it, being able to use loops instead of having to create a controlled system of relays that can potentially go horribly wrong! have no idea if blockland could support such a system of programming individual bricks to perform specific functions with such versatility, but it's worth a shot.
In short, this is meant to be friendly for beginners but could potentially have advanced features for more advanced users.