I spent a valuable couple of hours re reading the rules and taking time to clearly understand what they say and how you can apply them. For example, if you are rounding a mark from a run to a beat giving mark room to an inside boat and they take an excessively wide path around the mark, you are perfectly entitled to luff them and they have to keep out of your way until they get back to a correct course for mark rounding.
One of the best ways to learn the rules is to goto the rules pages on Racing Rules of Sailing web site HERE
On their site, under each rule is a number (see below) which when clicked on, provides a pop up window summarising cases arising from protests around this rule. Reading through each case provides different views on how this rule is interpreted. Enjoy.
Extract from Racing rules of sailing rule book
All the relevant information on rules sites is HERE