In reply to:
From what you've seen,
Is it safe to link to X (something I'm not sure if it's copyrighted or not) on other servers (rapidshare for example)?
That is a determination you will have to make - I always assume that anything not clearly stated to be freely distibuted is copyrighted.
Additionally, IMO, the "cracks" you currently link for download, that are stored on your own site, are *clearly* in violation of the ToS, and the law (cracks for commercial software, etc.).
In reply to:
I have no way of knowing if users are uploading images they made or images they found/stole. Will dreamhost be aware of that fact and send me a warning so I can remove anything against the ToS, or will they take my money and suspend my account?
Allowing others to upload whategver they want always brings potential exposure to you, both under the ToS, and the law (though that varies by circumstance and jurisdiction). I do not know what you could reasonably expect in the way of enforcement action from DreamHost; they have said each case is evaluated on an individual basis, and you should ask them for any clarification you desire.
You might note that, in the totality of the circumstances, you will be hard pressed to persuade DreamHost, or any other reputable provider, that you really are willing to obey the ToS and that you should be trusted, while you are directly hosting "cracks" and/or other material you cannot legally distribute.
Information in these forums indicates in some instances, like the "cracks" hosted on your site, you could well end up just having your account closed and no money refunded - that's a pretty obvious, and blatant, ToS violation.
There is a lot more information about all of this, including what to expect from DreamHost in the way of enforcement, on the DreamHost Abuse Center site.
I think if you read all that information carefully, you should have most of your answers - and that you should ask DreamHost directly for information on anything you are not clear about, as they suggest in those pages. 
--rlparker