Your insights are interesting but you have left off LR's prejudice against FW's outward show of brilliant yet potentially headstrong actions allied to his wits. LR sees this as a dangerous shade to FW's character leading to who knows where.

As to FW not thinking enough of Anne's position should things go wrong: a young energetic (and headstrong) man in first love, and with love returned, rarely thinks of anything more than action. Reflection comes later if it comes at all! If he is being selfish I do not think he can help it overmuch. Interestingly Anne's major motivation for breaking the engagement is the persuasion that she is acting in FW's best interests. Perhaps it is this comparison of selfless actions that resonates?