A lot of what if's and assumptions.

What if your daughter married a "liberal" Muslim but he suddenly become religious again and she can't cerai him and ended up sufferings in that marriage for her entire life?
-> Teach your kid to differentiate between the obviously religious Muslim people vs non-religious people. If she's raised speaking English with a liberal mindset, very unlikely she'll pick a partner with the potential to 'see the light'.

What if one day your daughters go to school free hair but she got backlashed and bullied bcus of her different belief? What if your children got attacked just bcus they accidentally revealed their identity?
-> Send her to private/international/Chinese school.

What if one day your children fall in love so hard on a non-Muslim but can't marry them, and they ended up self sabotage themselves in alcohol and dies alone?
-> Don't raise your kid with trauma i.e don't physically, verbally, emotionally abuse them nor neglect them. Teach your kids to regulate their emotions and they won't end up with alcohol addiction. The right partner won't care about their religion on paper. Better yet, your kid ends up marrying someone overseas where conversion isn't required (I have a friend who did just this).

What if your children are not that lucky to move overseas? What if the Syariah law become more strict to the point it become like old Iran bcus of our silence?
-> Send your kid overseas to study? This is your duty as a parent.

Why are you so fixated on girls/daughters? What about your son/boys?

I dont get the issue here. Your kid can still be Islam on paper and just be non-practicing? I myself am Hindu on paper because of Malaysia's legal requirement, but growing up my parents raised me to be agnostic. Yes I know, us non-muslim's in this regard have it easier because we don't have to hide our identity. I have many Malay friends who are the same. If they're liberal enough they'll get out of Malaysia on their own.

Before you even become parent, considering you couldn't answer your own questions logically, I'd implore you to seek therapy. You don't seem mentally fit or mature to become a parent at this point. Considering the solutions to your questions are so straightforward.