Should hate speech be allowed ?
You're bringing up too many issues to address at the same time.
You do not merely find these consequences acceptable/desirable as a matter of foundational feeling, they are too specific for you to have a gut feeling about, you would be thinking about consequences still. — Isaac
I think this is the most important thing to address first.
When ethical stance M is foundational for S on occasion O, all that means is that for S, on occasion O, there is no sentential (utterable-in-a-sentence) ethical stance "beneath" or "behind" M.
M can be any conceivable ethical stance.
How can that be the case?
Let's say that S is considering a situation where (this is a real-world occurrence I just heard about this morning) S was shot in the face at close range with a t-shirt gun at a sporting event, causing S to fall backwards, hit S's head on concrete, get a concussion, and have subsequent medical problems. S is contemplating whether S feels it would be morally acceptable to sue the team in question. This is a very specific thing to consider.
Well, in that situation, S can simply feel that either yes, it would be morally acceptable to sue the team in question, or no, it wouldn't be morally acceptable, where S's decision is simply S's intuitive or "gut" feeling, without S's decision resting on some other moral stance that S holds.
You apparently want to argue that this isn't possible (without actually providing an argument that it's not possible).
Meanwhile, I do that sort of thing often myself. I consider some specific dilemma and simply intuit how I feel about it. That stems in part from me coming to believe that principle-based approaches are not a good idea. This doesn't imply that no thought can go into it, but (a) the thought that goes into it might not be any sort of ethical stance, and (b) the thought that goes into it might not be foundational--and really it can't be if it's not an ethical stance, as no non-ethical stance can imply any particular ethical stance.