Well see the thing with BLC is at the baseline level they are not actually that strong. A close range BLC hit with increased shield damage that doesn't crit against a shielded target tops out at 900-1k. Which is pretty hefty however you have to remember BLC also has a very low RoF and again <500m.
A target caught unawares by that could still easily have time to respond, evade, and counter. Where BLC begin to get excessive is when you start throwing in crits which can go upwards of 1500, crits are what allow targets to be killed before they can evade. Crits are also what makes BLC so potent with TT compared to other weapons because TT takes BLC's already large crits and makes them even more insane. That's also why CF is extremely potent with BLC as well.
As for TT and quad'n'pods, the simple solution would be to make TT not effect secondaries,
Perhaps rather than doing sweeping damage nerfs to BLC, would be to first remove the passive crit chance inherent in BLC, and then more importantly cut down the base crit multiplier for BLC. So instead of BLC having base 50% crit multiplier it would have say a 20% multiplier. That way even if your stacking crit cooldowns you won't be able to reach the crazy burst numbers.
There are a few other things that could be looked at such as armor pen. I wouldn't remove the armor pen entirely from BLC but BLC should not exceed 50% armor pen imo.
Now Blaster Overcharge is a whole different beast. I would argue that BO is by itself overpowered and needs a direct nerf. (I've done 90k damage/20 kills with BO and RFL
The premise for my reasoning is that BLC are not by themselves overpowered, what makes scouts overpowered is that BLC/quad'n'pods+ OCD allow the scout to kill a target before the target is humanly able to react. After all when you are aware you are fighting against a BLC scout it is not that hard to defend against, keeping the scout from attaining a clear shot at <500m is easy to do even in a strike. However if you die before you realize the scout is there, that is where the unbalance begins.
As for nerfing the cattlescout's defensive capability, lets balance the burst build first and then see where the cattlescouts stands before anything drastic is done.