Questions about realpath() error

[TabulaRasa]

Now I know that this has been discussed here before, but here's my delima. My hoster has disabled realpath, and will not enable it. The only way the forums work for me is through the SMF Default Theme. Now I have a few questions about that:

1) Why does default theme work, but none others?
2) Is there any way to make a theme bypass the realppath() command?
3) Is there any way of editing default to where it still works, but has diffrent colours and images?


I would really appreciate it if you could help me with those questions, and I'm sorry if it's in the wrong forums