I agree with how drug bonuses work, Mithlas. They also don't mention they're limited by augmented limits anywhere. As you said though, they have addiction as a consequence. How much of one is largely up to the GM, but it's still a built-in function that stops them from being relied upon too heavily.
I wouldn't rule that bricking any kind of implants has an effect on the target beyond removing their ability to use it (which can already be a huge downside). Because I like hackers being able to brick stuff, but I don't want street samurai players to have yet another reason to bitch about wireless bonuses-- Especially when RAW there's no precedent for stuff like that happening. Like... Anywhere. Wireless matrix is only a decade or so years old in SR, but in that time I don't think I've read anything mentioning (in fiction or rules) a runner getting geeked because his 'ware killed him from the inside out. Runners dieing because they suddenly lose that edge at a critical moment? Sure. But unless it's biofeedback sent straight to the brain via Black IC or Black Hammer, nobody's just dropped dead (yet) from somebody crashing an internal implant.
Besides, Michael, aren't you one of the people who's against bricking having effects like that? I recall you stating before how you felt a bricked smartgun should still work as a gun just fine, but I could be misremembering.
If there's even some JackPoint rumors about that stuff happening though, I retract my statement.