by no means am i an expert or qualified to give legal advice, but from doing some research i am 97% positive that registering a domain name does not automatically entitle you to trademark rights for that name. so my guess is that in theory someone could register for a trademark for a name that you have already purchased. i think you would have to look for case law to see what if any rulings have been made in the past regarding this type of thing. i know that on the uspto website there is a subsection that sets out what constitutes different types of infringement and has many a reference to actual cases that have gone to trial and what the judges ruling was. if you are interested in developing the site you might want to consider spending the $30 to file the name as a tm w/ the uspto.
as far as i understand, generic words are not in and of themselves trademark-able. for example, while the term 'ABC Textiles' could be trademarked, just the word 'Textiles' alone could not, as it is a dictionary word in the public domain. also, i believe that courts have ruled that adding a .com to the end of a name does not add enough distinction that would warrant trademark consideration. so i don't think that 'textiles.com' is able to be trademarked either. hope this helps. but again, you might want to do further research of your own.