Hey, i think almost exactly like you about this.
I deeply hate java. It is maybe 150 times slower. But python is the only interpreted language that show me a quicker alternative to C. Also i have not seen too much (if any) speed downs becouse python is almost completely C. What a python script does is organize how other libreries should be called conforming a program, those python lines are normally only executed when the user interacts with the interface, like when clicking a button the script just tells what other control should be updated, the hard work is made in C.
Also i will not do this project in any interpreted language.
I say that it is very much like C, becouse out of esthetical features, each line could be directly converted to a analogous C code (more complex of course) and python provides an API to make it by hand. There are some tools designed to do that (python to C conversion) but i have never run into the need to use it.