4. I do not really understand how he (Trussell) could be so daring as to steal the Shrimpboat's car but not be brave enough to approach Ellen earlier.

         Yes that was odd (Cassidy and Ronnie also thought so), but sometimes that's the way the heart works.  In Trussell's case (and not infrequently with other males, I would venture) facing a physical danger or taking a big risk was easier for him than revealing something about his heart.  Trussell is not just asking a girl out for a date.  He is "showing his cards," as  he says, telling her that he really cares about her just by being in her presence, whether she realizes it or not.  He had rather remain inactive or face danger or take a risk than experience rejection from Ellen.  That may not be logical, but that is the way his heart works.  Trussell tries to explain this to Ronnie in Chapter 10 (pp. 178-180).  As you see, some people have very tender hearts.  And his had been broken before.

         Trussell finally realizes that he has to take action after Trudy makes a pretty determined pass at him.  That was the jolt he needed to make him get busy.