An answer to your flashing question. Over time the thin aluminum flashing they are selling does corrode a bit. I have changed my flashing twice in 33 years, once because I restacked the brick, and the second time because it actually corroded. The last time I thought I was doing a basic repoint andminor repair, and ended up replacing it all, had I known that before I started copper would of been used. When my final roof goes on (present one is 30 plus years, I will be installing copper. Both will outlast me
I also now coat the brick with a breathable water proofing, which is holding up well on the mortar joints, lot easier to go up with a brush a slap the clear on vs. repointing.