Lets see; yes you could turn pro. You could, tomorrow find somebody some where that would feed you to a lion for a dollar. Bt no, 17 isn't too old to start, though its getting there. Robot-like on your feet? Try pushing with your back foot like in fencing; watch fencers and how they move. Look, you find your stance and it should be where your balance etc is maximized; so keep your feet there no matyter where or when or how far you move. As far as slipping punches...when pracicing always practice with the counter punch otherwise why bother? Also, always move in behind the slip and counter otherwise why bother? When you slip keep one thing in mind; the moves you make are the exact same as a particular punch. Slipping a jab to the inside (over your right shoulder) is throwing a straight right. Over the other shoulder is a left hook. You slip on your feet; you move your head with your feet. Otherwise you will not be able to punch. Twisting and leaning is asinine when you can shift the weight on your feet avoid the punch and counter hard at any point. To the guy that was 5'6" and wanting to get ripped to fight HWs; constantly coming forward, straight into the guns, and having no other choice is a tough row to hoe. You could be an amazing wizard of defense but you will get hit and hurt a lot every fight because you have to constantly press in and stay in range. I read once that Marciano often had to work to get his mind ready to fight and win, knowing that he was going to be walking into a tremendous amount of damage