A1. There are two kind of kingdoms. One is a kingdom which the king, or one ruler governs and rules the entire kingdom of his or her country and divides the kngdom into districts and sending his various administrators there. Other is a country which is consisted into many group of hereditary who are recognized in that state be their subjects and who are loved by them, so the king cannot take away that place without making him dangerous. The example of the first kingdom is the kingdom of Turk. A country like a Turk is very hard to conquer, but once you conquer, or in other way, kill the king, it is very easy to control the country. The example of the second kingdom is the kingdom of France. A country like France is easy to conquer, but hard to control it, unlike the Turk.
A2. Well, it you became a master of a city, it doesn't matter if the people in that city is obedient. However, if the people in that city is accustomed to living in liberty, that city will always have a grudge against the master of the city, demanding their customs. I think that if the master of the city was a prince by birth, than he can be a good king, just keeping the rules by itself like it appears on the first part of the book. But if you are a prince who are not borned by birth, the people of the city will be more disobedient.
A3. Um, for me, the most important sentence will be 'since he possessed allies and soldiers of his own, he was able to construct whatever he desired on such a foundation.' on page 23. I don't know for sure when this story appears, but I have once read 'The Prince' in Korean, and realized that a king should show some kindness to the people, for example, giving them benefit, but a king should, no, must also have violence. Machiavelli is saying how to be a great and powerful king, not a kind and good king. So I think that the point is that. A king should have both violence and a little kindness and find a way which gives benefit to him. Even if that way is betraying allies. And, I think possessing a army of a own is much better. Sorry. I think this is not enough for the right answer.