Hello Attila,
The start of the game is always the most difficult part.
How do you have more troops?
Well, it's easy to explain.
Every building you construct needs a certain amount of population. Once you build something you'll loose population. Now, once your city reaches 10k points, it usually fulfills all the basic needs of a city, and the rest of the buildings aren't really needed. Which means that you would use more population to build an (unneeded) 13k city than to build a 10k city. So, you'll have the possibility to build a larger army if you only use the basic levels of your buildings.
Your second question: It has (indirectly) something to do with the size of your cities. Morale is calculated by a formula taking into account the total points of the attacker and the defender (I don not know the exact formula). If the defender has significantly lower points than the attacker, the defender will profit from morale which means that he gets a small defending bonus (as the attacker's troops won't be at 100% fighting power).
So basically, the lower the points of the defender, the better
Though, I wouldn't really change your game style based on morale. Just build your buildings to a 10k city, and make a good amount of troops and you'll be able to resist the attacks anyway. I always say, morale is for noobs
I hope my answer was sufficient.
Joris