but it turned out to require very circuitous routes to do simple things.

Unfortunately this about sums up the current state of 'real world' programming.

It is helpful to have a concrete goal to work towards rather than merely coding for the sake of learning. Learning 'on the job' is helpful in this regard as there is usually a somewhat defined set of requirements and there is added motivation and supervision that comes with being paid to write code.

If you are trying to learn on your own I'd suggest trying to set yourself the task of writing a simple program to do something fairly clearly defined and then work towards that. Simply reading through open source code (or any third party code) is not something I've found terribly helpful as a learning exercise. More useful is to set yourself the task of fixing a specific bug or adding a specific feature as this will help direct your investigation.

Learning how to use the debugging tools available to you is also important. Understanding how software is put together can be greatly aided by stepping through code in a good debugger.

C# is pretty good for 'real world'/GUI development. Personally I think it is the best option overall at the moment for that kind of programming but you will find language choice is a bit of a religious war issue.