4 Godless Shrine
4 Orzhov Guildgate
9 Plains
9 Swamp
2 Beckon Apparition
4 Cremate
2 Wear // Tear
2 Blind Obedience
2 Orzhov Charm
2 Gift of Orzhova
2 Profit // Loss
2 Obzedat's Aid
2 Dutiful Thrull
4 Thrull Parasite
4 Basilica Screecher
4 Tithe Drinker
2 Vizkopa Guildmage
4 Sin Collector
2 Crypt Ghast
2 Blood Baron of Vizkopa
2 Obzedat, Ghost Council
I consider FNM at least mildly competitive and sometimes very competitive depending on your area.
First off 70 cards is too many we need to get you down to 60+15 side board.
You can immediately cut these.
2 Beckon Apparition
4 Cremate
2 Wear // Tear
2 Gift of Orzhova
A BW "control" deck can be possible. However, you've got some pretty decent blue cards, so Esper midrange/control is actually probably where you want to go. there are several options here.
You can do the solar flare reanimator, esper control, esper midrange. I think you'd want to be more midrange though. Removal with some sweepers. Take a look at the decklist below. It's something you should look at.
http://sales.starcitygames.com//deckdat
ckID=56470
I realize the lands are expensive and sometimes hard to get, but I think you'd be happier with the results.
Extort hasn't been a mainstream mechanic so far, however, if you really want to stick with the theme of the deck. Then I think a B/W midrange is more where you want to be. It's important to remember that extort is a long plan, you're not going to come out of the gate swinging like a red deck. You want consistent plays that make value for you on the baord.
Go down to 20 or less creatures including bombs and a few extort creatures. Things like knight of obligation crypt ghast would be good. Basilica guards have a healthy body and can block well. Obviously your bombs like blood baron and obzedat are solid. An angel of serenity would fit in here as well. The tougher creatures with larger bodies would also allow you to play mutilate more consistently.
IMO the smaller creatures are either going to get removed or you'll be forced to block with them and they don't trade well. Sin collector might be the exception here. He provides knowledge and could even get some good value.
As far as spells go, blind obedience is good has the extort mechanic as well as slowing down aggressive decks. You need stronger removal, and it needs to be more direct. Murder, orzhov charm, dead weight, tragic slip, victim of night. heavy black, but direct removal is where it's at. Try to stay away from conditional removal like smite or executioners swing. You also need a sweeper of some sort. Look at merciless eviction and Mutilate. Mutilate might kill your own creatures, but it's better than losing to a more aggressive deck. Also, casting a spell puts the extort trigger on the stack so, even if you wipe your board, you can still extort with them first.
Lingering souls is a fantastic midrange card and the ability to cast it twice means you can extort off it more than once. Consistent, flying, blockers, evasive. I play them with sorin in a RBW midrange and they're like peas and carrots. This card gets my vote for top 10 in standard atm.