GP Strasbourg - getting ready

In two weeks time we are going to France to participate in Grand Prix Strasbourg. The format is Legacy and thus I tried to come up with a deck I'd like to play. I started with GW Maverick, GWr Maverick, Esper Stoneblade, Junk Rock and BUG Tempo but in the end a BW deck came out of it (with Abrupt Decay and Deathrite Shaman).

After preregistering and sending 45USD to the organizers I really need a deck that I like to play.

I like my deck so far but I'm not sure if it should stay the way it is. At before last GPT I terribly died (it was the only match I lost) because I couldn't deal with Grove of the Burnwillows and Academy Ruins can be pretty annoying as well. So I was wondering if I actually should play Wasteland. I decided not to play too many dual lands and thus have better match up against anything tempo and other disruption decks. This worked wonders but still there are some lands I need to get rid of and Vindicate does not sound that good either. Anyway I almost made it to Top 8 (due to my missplays I just did not make it but it wasn't the deck's fault).

During the short period during which I play with the deck I made few changes. I added one more Umezawa's Jitte because many people are simply playing more than one and there are Decays everywhere. I cut Oblivion Rings and added 3rd and 4th Deathrite Shaman. But after last two tournaments I decided to go back to 3. The Shaman was actually one of the cards I usually sided out. Instead of that I added one more Lingering Souls and it 's quite ok.

My sideboard more or less consists of 15 random cards and I will most probably change the discard cards. I should play Thoughtseize as I need to deal with Jace TMS and Batterskull for example and play less Cabal Therapies as I will be playing against people I've never seen in my life and I won't know what they play thus. So 4 Thoughtseizes (I don't have those...so we'll see if I can get them) and 2 Therapies should be the right number. I was also wondering if I should run Pernicious Deed or Engineered Explosives. There are times in which I would really appreciate a card like this and match ups as well.

Anyway if you have any ideas that could help me or some feedback just comment underneath this post. I'll appreciate it. The decklist follows.

BWg Stoneblade
stsung
Legacy

Main Deck:
4 Dark Confidant
3 Deathrite Shaman
3 Liliana of the Veil
4 Stoneforge Mystic

4 Abrupt Decay
1 Batterskull
2 Bitterblossom
3 Cabal Therapy
2 Inquisition of Kozilek
4 Lingering Souls
2 Sensei's Divining Top
4 Swords to Plowshares
2 Umezawa's Jitte

2 Bayou
3 Forest
4 Marsh Flats
2 Plains
2 Scrubland
5 Swamp
4 Verdant Catacombs

Sideboard:
2 Ethersworn Canonist
1 Mindbreak Trap
2 Nihil Spellbomb
2 Oblivion Ring
1 Perish
2 Pithing Needle
2 Surgical Extraction
1 Sword of Feast and Famine
1 Sword of Fire and Ice
1 Zealous Persecution