Though young, his long back was already bowed, and he walked with a forward thrust of

Though young, his long back was already bowed, and he walked with a forward thrust of
 

-Though young, his long back was already bowed, and he walked with a forward thrust of his head and a general air of peering benevolence.

1. Does FORWARD THRUST mean occasionally his head would move forward/jerk forward? Or is it just a slant?

2. What does GENERAL AIR OF PEERING BENEVOLENCE mean? I understand every word, but their combination puzzles me. Why is AIR depicted as GENERAL? Dictionaries have many senses and I can't pin one. BENEVOLENCE means kind, helpful and generous, but how does PEERING come in? Does it mean when that person looks (=peer) at other people he shows kindess?

I sounds like 19th century British literature. The way people describe things has changed and individual authors have their style which may not reflect anybody's speech. Walking with a forward thrust means walking head first as a person who is hunched over may do. I think peering benevolence probably means looking over things in a kind way. In context this meaning may be different, however.

Thank you~