They require writers, at least in my case, to provide identification documents including driver's license, id card and (not or) passport. Then a few days later they ask for Skype and personal phone numbers. Any comments?
Yes. They sound like they are out to steal your identity rather than simply setting up your account. That is way too much information based on government based ID systems of any country, for you to share with any company that does not truly require (read: not government mandated) any KYC procedures. Do not proceed with signing up with any company that requires government issued ID's as a part of the application process unless it is a reputable and publicly known company. In this case, it sounds more like the company is preparing for use your credentials for fraud than anything else.