Objective morality as a proper basic belief

[The Grand Nudger]

Khem, I already explained how you can insert whatever fucking base principle you want into your good/bad meter

No, that's my point..in an objective moral schema we can't just insert whatever base principle we want.  

and just because they're fucking wrong as fuck doesn't mean that ISIS isn't using their misguided religion as their metric rather than well-being.

They are using well-being.  They simply disagree with you as to what does or does not promote or harm human wellbeing, as to what prmotes or harms it more.  An objective schema might help to determine who's right about that, wouldn't you agree?

I agree that well-being is the only sensible metric to use and for good reasons but you can't argue that there aren't different axioms or whatever that you can jam into morality machinery of your brain no matter how ill-fitting they are or how much damage they cause that machine.

Objective morality doesn't argue that, as a subject, and harm or human well-being isn't the only basis for objective morality.  There's more than one objective moral theory.  The harm based one is just well suited to conversation for it's simplicity and focus on an individual moral agent.

I agree that the DICTIONARY definition of morality should revolve around well-being which it very well might. Thing is there are lots of zealots who would disagree and their existence makes this caveat necessary.

You have a misunderstanding of those zealots.  They are trying to do the good, as they see it.  They are trying to help, and to prevent harm.  They simply lack the objective schema that would be required to disabuse them of their misconceptions about what is or is not harmful.   Now it might be, that, if you presented them with it..they shouted allah hu akbar and chopped your head off...but that would be because their religion or culture has morally compromised them.....  as their day to day activities strongly suggest, lol.

But please, fucking enlighten me, since I can't see a way around the above.

You aren't presenting an obstacle to get around.  You have misconceptions about objective morality, and about religious zealotry.  Imagine a person who was as deeply commited to say, humanism...as a suicide bomber is to their version of islam.  They're both zealots, one of them a case study in how religion eats the brain and makes people generally shitty...and the other a terrifying obstacle to people like that. The difference between them, is their moral schema, but not much else.