Since you can define variables for use in your codeblocks, I think it should not be too hard to publish those (or some of them) to be changed by the person using the object created by your code block.
For example, you could flag a variable as public or private. If an object created from a codeblock is being used and has at least one public variable defined, the user gets a little dialog where he/she can change the public variables' values (similar to what you get from the forms generator).
Being able to define min and max for those variables could be helpful as well, but being able to control variables from the outside is more important IMO.
Apart from that: Great job!
[Edited for typo]