The axe stops if it hits terrain- that means walls, turrets, inhibitors, and player-created walls such as Anivia's ice wall, Jarvan IV's wall, and Trundle's pillar. In order to make the axe go further, move your mouse further up. When you're CSing, try to save your axe since it costs a lot of mana to use and you're usually better off using it to harass the enemy laner. (Also you should really try him in the jungle- he's super fun and you get to spam your axes more so you can get more practice in using them.) Tiamat isn't necessarily the greatest item on him, IMO, but it can work- I suggest just building mostly tank with 1 or 2 damage items. And if you do decide to do that, you can actually pick up that Tiamat and turn it into a Titanic Hydra for more damage from bonus health. When ganking, yes it is ALWAYS best to throw the axe first, since it gives you a free slow and makles the enemy much easier to chase down. ALSO the cooldown resets when you pick it up, so even if you miss you can just walk up to it, pick it up, and throw it again. Try to save your ghost for when you use your ult, that way you can basically just run up to anyone on their entire team and smack them to death for free. Hope this helps! Any more questions feel free to ask :D