I registered a lot of domain names under .eu I got some which are trademarked, but since I sell their product, there is generally an agreement that the trademark holders leave me alone, even support me! Some of my .eu have not been renewed and I suspect that this is because Euroid the governing body have flagged me as an example and and are preventing this reregistration. Silly becuse I hold the co.uk's anyway. Can they legally take a domain from you, site and all, without a court case??
I'm not sure if that is what happened, but to answer your question: Yes. ICANN, which controls the big TLDs, has the UDRP. Think of it like a web host that doesn't have to go to court to take down your website if they are informed of copyright infringement.
If you violate any term of your agreement with them, yes. Then again, they can also do that anytime as long as they retain full overriding control. Incidentally they're taking a Chinese woman to court over something like this.
gongratulations mate. if you were ripping them off or selling your own products and saying they made them, then they can take legal action, but as a few have mentioned, if your selling their products under their name and are complying with their terms and conditions, you shouldnt have any problems there. good luck with it all mate