Would the trademark holders have any right to prevent my usage of such domain names?
I'm looking at a somewhat generic trademarked two-word phrase which has several trademarks registered for it related to different products. If I register domain names which contain the trademark, what rights do trademark holders have to challenge my ownership of the domain names? My domain names are clearly related to a different product / business than any of the existing trademarks.
It may not matter what rights they have or how likely they are to win, if you don't have the budget for a legal battle. Also, why start off with words that are associated in people's minds with other people's products? It would be an uphill struggle to get your brand recognised. There are thousands of other words to choose from, and if that fails, make some up.