Is .info domains have any problems as they are cheap ?

Answer 1

Not as far as I know. The reason why they would be cheaper than a .com domain name is because a huge amount of the obvious .com names have already been registered eg. computers.com.

The problem with .info names is that if you have a website called computers.info, people might only remember the "computers" part (if they haven't bookmarked it) and type in computers.com instead. For a commercial site this could prove detrimental to business.