I read through the rules yesterday, they seem pretty straightforward. The only one that is grey/fuzzy is the stalling one. Perhaps that is intentional. You may want to give a general mantra on what you consider stalling so that people who are newer know what they can/cannot do. Like taking 3 days for every turn is not stalling, until the game is basically lost. At that point, you are stalling. I don't know what stalling really accomplishes in CL anyway (outside hoping for a boot). People do it in ladders, I assume, to manipulate matchups/ranks.
It is indeed intentionally kept vague, as there is no clear definition. Let's say that if you're dragging out the league significantly by stalling, you'll probably know what you're doing. I will warn first of course!
The stalling rule came because Avengers was playing to elimination at 3 days a turn in the Qualifiers (CL11) This pushed the next stage of by over 2 months.