I did read the sticky thread on sweet spot testing, but it seems like it is more geared towards the nones.
How do you sweet spot test for IO, IH, and IS? Can you actually OD on these products? Do you know it’s too much when random strangers come up and start telling you where they hid the bodies in their back yards? 
Maybe it’s too much when you can’t get other people (or yourself) to shut up?
Also, with A314, I am not sure what the responses will be when you have too much on.
Its all the same for everything, it doesn’t really matter. Feel things out - not all of the answers can be found from other people, you need to have some self-discovery too so that you know what it feels like to you.
Yup - Use the sweet spot guide as a starter but you will need to use a little more judgement with socials. And yes, all your scenarios are kind-of possible.
Also feeling tired/drained/headachy/giddy after a few hours of use/topups can be a useful warning-sign.
That’s another thing I was wondering about. Whether you can OD on self-effects and crash and burn. Worse yet, putting too much IH on, having a few beers, then have a “I can’t believe I told this person that!” moment. 
As John suggested, I think I will just have to test for my personal limits. I was just wondering about the experiences of others.