GamePlayManager.py should be fine, the first error would be caused by the ltk.py file using it incorrectly. It seems like your biggest issue right now is indentation and not including all the needed callbacks.
Indentation is a huge part of the python syntax, most of what would be accomplished by curly brackets in other languages is accomplished by indentation in python. Anything on the same indentation as another statement is considered to be in the same scope. Right now you have lines like "self.warmupTimer = GEWarmUp( self )" outside of any callbacks which will cause plenty of issues. You'll want to include the "def __init__( self ):" definition, similar to the one in arsenal, and put that there. More or less just do that for all the statements and you should be good. Make sure they appear inside the right callback, otherwise they won't be executed at the correct time.
Just remember:
def addNumbers(a, b):
return a + b
could appear in C++ as
int addNumbers(int a, int b){return a + b;}
but
def addNumbers(a, b): return a + b
would not work in python because it doesn't have proper indentation. Same with
def addNumbers(a, b):
return a + b