Maybe. Maybe not. There is no plan.
Maybe someday. Maybe never. If you want to see something happen, you can do it yourself!
There are no ISO images. This project does not cater to non-technical users.
That's what Andreas was most familiar with when starting out. There's some interest in supporting 64-bit systems and that will eventually happen, but it's just another feature.
If it builds on CI, it should build for you too. You may need to rebuild the toolchain. If that doesn't help, try it with a clean repo.
If you can't figure out what to do, ask in the #build-problems
channel on Discord.
The SerenityOS project tries to maximize hackability, accountability, and fun(!) by implementing everything ourselves.