Hearthpwn

You, obviously, want to mulligan for Undertaker and Clockwork Gnome/Zombie Chow and also Power Word: Shield.  Always get rid of Shadow Word: Death, and anything that's 4 mana or more. I tend to keep Shadowform if I get it in my opening hand, but I don't usually mulligan for it. If you go second keep Dark Cultist.

I've been doing pretty well against Handlock. As long as you keep board control, and don't throw tons of minions on the board all at once, you should do fine (except if you have bad draws). Try to save Shadow Word: Death for a giant and Lightbomb for when they play a ton of giants and high attack minions. Mass Dispel can also help with getting rid of their taunts to either trade with minions or hit their face to win and to take care of Twilight Drakes.

Against aggro, I've found that going into Shadowform as soon as possible helps. You can usually start pinging off most of the minions they play and then trade well against their bigger ones. Deathlord sees great value (most of the time) against aggressive decks, because of its high health. If you can keep it alive by healing it and giving it Power Word: Shield, it can basically keep a lot of early game damage off of you and again help when you start pinging off with Shadowform.

I think you would do the standard mulligan (Undertaker, Clockwork Gnome, Zombie Chow, and especially Power Word: Shield). Don't play an early game minion (except maybe Clockwork Gnome) if you don't have any way to buff it, because of Fiery War Axe. After that just try to control the board and don't play too much stuff.

I haven't calculated any win/loss ratio, but I'd take a guess that I win with this deck around 65% of the time.

 *I haven't really faced much control while playing this deck so this is mostly just an educated guess.