Wait... so your father wants you do slow down?
No offense your father, but if you want to throw harder, you should practice faster tempo of your delivery. I mean, faster delivery basically equals faster whip of the arm and guys like Tim Lincecum, Joel Zumaya or Matt Lindstrom basically demonstrate it. Read this link for a more description: http://www.setpro.com/NEWWEB/mmax04.htm
IMO, your tempo reminds me of Kyle Lobstein, the Rays' 3rd rounder this year. He's more of a 'pitchability' guy rather than a guy who'd blow 95mph by a hitter. If your goal is more velocity and if you are willing to increase your tempo, I'm all for it, but the thing is you have to work on your timing first, or else, it won't be any better than the one you have right now.
Other than your tempo... you look pretty effortless and the fastball seems quick to the plate. I'd say that you're pretty gifted guy.
Your arm action is fine. I'd like to see more aggressive finish from you if your goal is velocity now... but overall, it's better than most of what I've seen lately. I don't see much wrong about your delivery after that....