[Overtaxed]

I don't see him doubting himself or his duty in the books.

I agree! Aragorn (in the book) never had any doubts about taking up his kingship. And he was a tested leader. Read Appendix A about the Stewards of Gondor. Aragorn saved Gondor from the Corsairs using the name "Thorongil".

[g'nad]

And he was a tested leader

Lead the Rangers in the North for many a year...