Apple is in the business of selling hardware and accompanying it with software and cloud services.
They have zero interest of Mac software running elsewhere. They do have an interest for other software to be runnable under macOS / iOS without a major porting effort, but not a very great interest, I suppose.
Not while being compliant with Apple licenses? And you're beholden to Apple for a developer ID and permission to distribute applications, which they can revoke on a whim?
Given that running a Hackintosh often still requires using random unverified kexts from the net, I find it somewhat irresponsible to push applications built on such a system to your customers/users. How can you be certain that none of the kexts is backdoored and the attacker uses this as a vector to add malware to applications?
You can run Hackintosh on KVM just right away, although there are practically no 3D acceleration (unless you opt for PCI passthrough) and the performance is really tearful awful, still, it runs Simulator just fine.
No, you can compile directly in Linux. You need to build the tool chain yourself, extract the SDK from official sources, and use third party build tools.
