I’ve never had to deal with Broadcom drivers or pinned the kernel, so I can’t tell you anything about that. The LTS kernel (currently 6.6.32-1) still updates regularly, albeit not nearly as often as the stock Arch kernel, so that means fewer updates that require a reboot.
Just install linux-lts
and linux-lts-headers
via pacman, and you’re good to go.
Now there’s an idea.