Thank you very much for the update. We do appreciate you posting your thoughts of your new Presa here.  Thank you for sharing.

I had an article by Charlie Lafave that will shed some light on your pups behavior. I thought is was posted some time ago but I just gave it a new date so it will be visible on the front page again.  Just in case you miss it here is the link.

Some of the behaviors you describe is quite normal at this stage of his transition to maturity and you will see a sharpened sense of property and protection as he gets older. I would not try to hard to increase his prey drive at this stage because he will naturally want to chase furry things as he grows. You may put him in over drive and that could cause problems.

At this age he is supposed to have the attention span of a gnat and be interested in everything - all the time. His world is exploding with cool stuff and he is trying to check it all out.

I would not worry about him wanting to play tug o war with you.  He is probably teething and that may be causing him some pain or discomfort though he does not know the reason. This will also change as he grows. 

So, at this time I will recommend some patience on your part.. :)  let him be a pup and train the social attributes you want him to exhibit as an adult