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As a plumber this looks like a nightmare and the only solution in my eyes is remove more concrete and relocate that water line so you never have to deal with this again.
One of the competing options is indeed to tear up a bit of the plaster+lath bedroom wall on the other side of the wall, then remove a brick or two. Strictly speaking, I’m supposed to get planning permission to mess with structural walls (& IIUC all brick walls are structural). Not sure if it’s realistically important to get planning permission to knock out a brick.
Depends on the kind of brick. Cinder block, most likely yeah. Orange bricks? Those are usually for looks, or to cover an outside wall. They’re too thin to be structural. Well I’d hope so anyways.
Probably against code everywhere to have a shut-off valve inside a shower, but I’m not a plumber. I’d relocate it anyways. No matter what you do it’s asking for trouble if it stays in there. But you should ask a plumber in your area, they would be familiar with the necessary codes you have to follow, especially if you’re renting out those units.
Orange bricks? Those are usually for looks, or to cover an outside wall. They’re too thin to be structural. Well I’d hope so anyways.
Clay bricks can definitely be structural, and often are in older buildings. The key is that when they are structural, the wall will almost1 always be made out of two or three wythes instead of just one. If you’re trying to figure out if the wall has multiple wythes but you don’t have access to look at the sides/top/thickness of it, you can also tell by the fact that there would be occasional half-width bricks every few courses (because those bricks are turned 90° in order to span two wythes and tie the wall together). If the entire height of the wall is running-bond with no interruptions, then it’s very likely1 again a brick veneer and not structural.
1 Apparently there are exceptions where a structural wall can be made out of only one layer. I’m not sure I’d trust a building built that way, though…