Perisno - some questions about sieges and army composition

1 - which tier of troops should I get, before getting strong enough to win a siege by my own? 2 - what’s your usual composition for a siege? 3 - what’a your favorite faction to join? 4 - what are some good ranges units , apart from the elves? 5 - what do you do while the kingdom’s at peace? 6 - what’s the best way to level your companions?