I very much like the way you are using ‘intolerent’ — if I understand it right — as a way of saying that you will answer and engage with speech you don’t like.
One of the (many) problems with being fully intolerent (ie not allowing) of hateful speech is that the ideas are driven out of the public domain but not stopped — or answered. So such messages reach fewer people, but they do so without counter messages and they also then come with the tribal context of ‘they are out to get us’. This increases the social distance between ‘them’ and ‘us’, amplifying the hatefulness on both sides and sustaining the apparent and now real differences that drive the hate in the first place. You can see this with skin colour (white ‘extremists’ and black particularly in the States) and culture (islamic ‘extremists’)
Keeping ‘intolerence’ open and focussed on the ideas and the context, not the people and your/their tribal identities, is worthy if you can sustain it. There is nevertheless a danger of this sliding into banning and censoring people when the intolerent mob turns up; this is not a ‘sliding scale’ argument: it happens as you have found.
On a side note I find the ‘intolerent only of intolerence’ argument a bit iffy. I don’t think domestic violence should be tolerated but that isn’t quite what is meant by it; we all have ideas and activities we don’t want to tolerate and resolving those is tricky if can’t work out the common ground. Milo didn’t tolerate muslims at least partly because islam (in his assumed stereotype) is intolerant of gays or jews, and the ‘intolerence of intolerence’ meme frequently goes down similar stereotyping paths.
