Look up any reputable source detailing the laws of logic, you won't find "the law of causality" in there.
No, the point is my ad hoc being has exactly the same amount of evidence as your god does. That should be a problem for you. That's not to say that many interpretations, excuses and beliefs regarding the Christian god also come from an ad hoc basis. Just look at some of the rather wild claims on this forum.
As for people claiming to have a relationship for 2000 years, that's irrelevant. Not only is it an appeal to popularity fallacy, however there's been people claiming to have relationships with other mutually exclusive gods for ages as well, some even longer than 2000 years (i.e. Hinduism).
As for your last claim, how is the Christian worldview testable, and Christianity and god falsifiable? If you can actually provide something along those lines, we'll be in for a very interesting discussion.
Here's a relatively short video detailing the evolution of the eye, showing intermediate stages in the eyes development in species that are still alive today.
That's a shifting of the burden of proof. You are claiming that they were designed for a purpose, yet you can't demonstrate a designer or actual purpose. That being said, the video above does give the basics of how a structure like the eye can develop using natural processes.
Your turn to show your designer and prove his intent.
Think about any major complex work, it's always been designed and built by committee. It took thousands of people to design the space shuttle, or build the pyramids. The universe, while having an artistic element is largely all about physics, and if it were designed, engineering. Any major engineering work I can think of was not a one man job.
Regardless, it's a silly argument anyway.
Interpersonal relationships may be a problem, however there's no reason why someone with multiple personality disorder couldn't have well organized personalities.
Not really
And that doesn't really matter much.