I don't really think having a bit of a sloppy trigger rather then fifteen clean ones is a good thing.
Scripting should, and always should be efficient to avoid unnecessary trouble and bug.
Read this tutorial of mine, it would explain a few way to make it simple and it also explain why it should be clean and efficient.
Well, this is why I don't make many popular maps.
Creating a popular map are not meant by recreating something that already been done over and over again such as the TD generic of yours, which lack of interactions and uniqueness.
Making a map great is a very, very difficult matter and not as easy as you think it was. For established genres, lots of that can be cut away by seeing what works and what doesn't in other maps, but you need to seriously think and plan it.
Being fun needs the right balance of lots of different qualities, and that's something that's very hard to achieve, and will always, even for professional game designers, be hit and miss.