Question about remodeling an already finished attic

Hello,
I own a very old house. Built in 1878. The attic was turned into a recording studio which was the icing on the cake for me. It's been 5 years now and i wanted to do some remodeling. So far everything has gone well until now. The (I believe called) knee walls had no insulation except a handful of blown in. The wall was actually just a layer of tyvek with a 1/16th" piece of paneling over it. There was just a century of brick dust and dry powdery mortar. What i'm wanting to do is to create little isolation rooms. A place to put say your guitar amp so you can still play in the room with your drummer and not have the amp blaring in the drum mics.
I have two questions. First, if you look at the photo of the exposed area, there are slanted pieces wood acting as braces. But they really aren't. they're very loose. I wanted to either remove them or at least shorten their distance so that i can have a flat back wall half way from the opening. Are these still necessary for a house this old? If so, they're loose and i need to reinforce them. Otherwise i'd prefer to just leave them out.
My second question concerns the brick. It could definitely use some tuck and point, but was wondering if i would still need to do tuck and point if i'm just going to insulate the whole thing. I have a tank of closed cell insulation and was considering covering the brick area and then using bats for the sub floor before constructing my actual floor for this area. Below are images i hope illustrate my long winded dilemma. Any help/suggestions would be most appreciated. Cheers and have a great weekend.

Shaun Hamontree

 

I wouldn't remove those pieces of wood. looks like some of them are holding up your wall [even if they're loose] and others are bracing the roof rafters. My house is dated 1910 and I have those upstairs, but unfortunately I have no accessible space, unlike yours.
the roof rafters have to bear "snow weight" - they do this by transferring the weight to the outer ends of the rafters that rest on your walls. if your rafters are 2/4 or 2x6, they need the knee walls to bolster the weight transfer to the ceiling joists, which are also bearing down on the walls. look at it as a sort of truss.
if your brick is crumbling, I'd call someone in to get their opinion. I wouldn't just spray foam as yet.

 

Yep Hayzee is correct you cannot remove them (loose or not) without re engineering the rafters or building new supports. It's hard to see from your pictures just where in the rafter run they sit across the attic area.

I love that room though, that is way past cool !!