Opera Coast has build in security details for each page you open. You can verify any page if it's safe enough by tapping right hand bottom button and then swiping down page item your interested in. Here you will get safety summary, but you can get even more details by tapping security circle. There you will see information about Encryption, Reputation and Trust.
Opera Coast will warn you if there is danger from a site. However if you're interested in possibility to disable some pages using Apple's parental controls or something similar, there is not any right now.