They are all individuals. Some like to be stroked, some like a roughhouse, some like scratching gently. We have had cats that didn't like to be touched, but would head-but in affection. Most Siamese like a deep-tissue stroke which flattens them out on the floor. Some like to pull their tails through your grasp, some will only accept stroking in certain places, such as between the shoulder-blades. You have to find out what they prefer, and it will probably NOT include picking up. Young children quickly spoil that for a cat.

Squint at it. In Cat, that is non-aggressive. The reverse applies with dogs. Cats raise their tails and touch their friends with them as they pass. Put your hand down to eyelevel before petting, as some cats see an overhead approach as aggression.
And yes, you do have to be Alpha. Our cats know that a shout and a clenched fist means 'Quit NOW or you will be slapped!'