Secrets and a Passage to Deathrattle Rogue

Hey everyone!!  Here's another Meme deck I've been trying lately.  And once again, PLEASE CRAFT AT YOUR OWN RISK!

Trying to make Deathrattle Rogue work.  Here are my notes so far:

Valeera the Hollow - Prob doesn't belong, but she is fun and can provide some cool late game plays.

Spiritsinger Umbra - May not be necessary, but it does fit in here nicely.

I'm wondering how may Silver Vanguards and 8-drops to include.  Maybe a second copy of Deranged Doctor?  Kel'Thuzad could be good as well.  I'm also not sure on how many Backstabs, Preparations and Secret Passages to run.  Maybe only 1 Evasion?  Cheat Death could be good too.  I like everything else in the deck.  I might try a Potion of Illusion.  More testing....but I'm enjoying playing this archetype atm.