If there's no free will, there's no purpose to examining the question of what we "should" do, because we're just going to do whatever we were going to do.
You're conflating free will with volition, agency, the ability to assess outcomes and act accordingly. It's already been discussed here upthread.
Unless you're mentally impaired, or a child, or not in possession of relevant data, then you can assess outcomes, and act in consonance with that assessment. That volition, that agency, it carries responsibility, and it is grounds for culpability for the outcome of your actions.
But true, you can't possibly have acted differently than you actually did. On the face of it that may appear contridictory, but it isn't really, if you think about it a bit.
As far as I can see it, the free will question has nothing whatsoever to do with the question of taking and assigning responsibility. Those who imagine it does, IMV they're conflating agency and volition with free will.
When it comes to redress, to fines and jails and executions and the rest of it, then that is a separate question; but again, that question too has nothing whatever to do with free will per se.*
*Unless of course someone's approaching this from a religious perspective, and holding on to some cross-eyed biblical eye-for-an-eye thing. In that case you'd need to show such half-witted bible-sucklers the error in their thinking, and sure, discussing why they're wrong by explaining that there's no free will might be one way of going around doing that. To that limited extent I guess the free will quesiton might indeed be relevant. But bar that special case, I'd say, and IMV, to say that "You can't have responsiblity if/because you don't have free will" is exactly of the class of logical error as to say that "You can't have morals if/because there isn't a God".
everyone acts as if Free Will is an actual thing.
It's a bit of mental masturbation to intellectually say it isn't.
See above.
As I see it, to take the line you've taken above, is to say something like, "Everyone acts as if eternal life is an actual thing, and God is an actual thing, and God-given morals as well, and the consequences to abiding by or going against those God-given morals; and it is a bit of a mental masturabuation to intellectually claim otherwise." While acting "morally" means does need you to recognize the validity of morals, but it has nothing to do with whether those morals are absolute.
Likewise, what you're referring to here is recognizing the validity of volition, of agency, or the ability to assess outcomes and to act accordingly. Whether one has the ability to have acted differently than one in fact did ---- which is what free will amounts to (and no, one doesn't have that ability) --- is a completely separate question. An irrelevant question, actually, operationally speaking at any rate, in the same sense as the absolute-morals question in the preceding paragraph was irrelevant.
I don't need absolute morals in order to recognize that morals are a thing. And I don't need the ability of acting independently of precedent causes in order to recognize that acting responsibly is a thing, and in order to recognize that assigning responsiblity (and culpability) for one's actions is a thing.
eta:
arthwollipot had said upthread (or possibly in another thread, actually, but whatever) that while we don't have free will, but it makes sense for us to act as if we do. I'd found that a very reasonable approach at that time. But having thought a bit about this, thanks to this thread (and the other thread on free will), I'm starting to agree with
Olmstead that that apparently reasonable approach is actually incoherent. What is called for is not to pretend that we have free will despite knowing we don't have it; instead, what is called for is to clearly recongize the difference between free will and volition/agency, and to clearly understand what exactly free will amounts to (and let's not forget that at the end of the day it is as much of a religious idea as are soul and God).
What arthwollipot's approach does is make use of the commonly prevalent conflation between free will and agency, and works with that conflation instead of correcting it, and attempts a workaround for arriving at the correct solution despite acting with incorrect premises. To that extent it works, sure. But, and like Olmstead said upthread, and I'm starting to agree with him, this is actually an incoherent piece of reasoning, that somehow manages to apparently square the circle (by working from an error, and suggesting another error to correct the effects of the first error). Far better, and far more coherent, and far more accurate, to directly correct the original error itself, is what I've now started to come to see.