Yes. Don't listen to anything that's too loud!
It's a tricky issue, and you're not the first to ask about it. The best advice is to try to have access to your speakers gain controls at all time. I have my main mixer right beside my workstation and I've gotten into the habit over the years of always turning things down when I'm about to try something.
The 32768 value refers to the fact that 16bit audio has 65536 different amplitudes regions. If you don't set 0dbfs to a value, then 32768 is the maximum amplitude you can have without clipping. The intensity of the sound you hear will depend on your speakers.
By default, new Cabbage files always set 0dbfs to 1. This means all signals, summed, must be less than 1 or you will get clipping. Again, this could be as loud or quite as your speakers are set to.
As I said earlier, the simplest is to just be careful with your speakers. If you can run things through a little mixer then it's really simple to control this. If you are doing everything through your workstation this is a little trickier as it's a real pain to keep opening the audio settings.
One thing i also do is add an overall gain slider to each instrument that defaults to 0.1. I then multiply all outputs by this value. It means that each time the instrument loads it reset back to a safe listening level. It can get annoying that you must keep increasing the volume each time you make a change, but when you're working on new sounds it's not always a bad thing.