Immediately after downloading the Tor browser I went to the options page and saw that the 'Block dangerous and deceptive content' box under 'Deceptive Content and Dangerous Software Protection' was not ticked. Is this the default setup? Would ticking the box cause a problem with the Tor browser?
That option is a Firefox option, not a TBB specific option
As far as I am aware of, it will harm nothing
However, beware it is powered by Google Safe Browsing and Google is well known for their analytics, tracking, and general anti-privacy