Since you are probably recording and mixing with 24 bit, clipping is no longer a problem (okay, you can still do it, but the meters would have been in the red for a long time before digital distortion starts).
That being said, I gain stage similar to you. All plugins that produce harmonic distortion react differently to different input levels and with the level you choose you can't go wrong.
What can you do about the busses? Since the system is running on 24 bits, a lot.
- Turn down all faders to -4 dB and start mixing from there.
- Put in a gain plugin at the beginning of the bus.
- Use the plugin chain on the bus to reduce the gain.
- Turn down the single channels with a gain plugin at the end.
- Just turn down the fader of the bus.
Some of these options prevent the clipping of a bus, some don't. In a modern DAW, it all doesn't matter.
The only thing to be aware of is the level a channel or bus has, when it goes into a plugin that creates harmonic distortion.
At this point input and output gains in plugins come in handy, either to set the right input gain or to set the right input gain for the next plugin by setting the output gain.
On the other hand with 24 bits "if it sounds good it is good" is absolutely no problem.
If you have compressors or distortion plugins on a bus, you have to be more careful, because then mixing the channels will change the way the busses sound (mixing hotter will lead to more compression and/or more distortion). Adjusting the input gain is important, there.
Did you record too hot?
No, if you record too low you will introduce noise. But even for that you will have to record very low with a modern DAW.