Alright, here's what I'm thinking. I've switched Crush the Weak, Advanced Traps, and Web Palace around so that they are obtained at level 8, 4, and 6 respectively. This is because I have removed Spider Guards from the Web Palace, and so I want the ability to make traps to be obtained first to keep it defended. Of course, traps alone aren't going to keep the palace safe, so I also included an ability to the Leng Spider a sort of constant Tremorsense as to the activities in the palace, and the ability to warp there once per day as per Word of Recall while in contact with webs. It can only warp there, though, so it'll have to find it's own way back to the party should it choose to activate this ability. Additionally, enemies within the Web Palace are Shaken, and the Leng Spider can use the "haunting beauty" of the palace to Fascinate enemies, and attempt to wrap them up while they aren't paying attention as long as it manages to remain hidden.
The final ability let's it add it's full ability score modifier to ability DCs while within it's Web Palace, as a sort of homefield advantage.