Ed,
The last intuitive application I used was Candy Crush. Outside of that everything has a learning curve and ByDesign is no exception.
Account Determination Groups gave us a bit of trouble during implementation and I can't say that we fully understand their purpose and use even today. But we don't revisit them very often post-implementation. Project Management is not overly intuitive either so you have picked a couple tough areas to get stuck in.
There are some really smart and experienced users on here. You might get some specific answers to more direct questions you have. Many of the questions and answers on this forum go over my head but someone here can probably help.
Jim