The very reason we have two words - 'opinion' and 'belief' is that they do mean subtly different things - although there usage does overlap in daily speech...
An 'opinion' is a subjective statement about an issue, that is either an emotional response or a personal interpretation of some information. An opinion may be supported by arguments or facts, although people might draw opposing opinions from the same facts. Opinions can change when new arguments are presented. It can be argued that one opinion is better supported by the facts than another, by analyzing the supporting facts.
A 'belief', on the other hand, is a mental acceptance of a claim to truth regardless of the lack of supporting empirical evidence or facts. A belief will normally be kept despite facts being offered that counter it robustly.
Either way, you do not need 'qualifications' to hold opinions or to have beliefs. You can shape people's opinions by rational argument [e.g. 'Synthetic life is good because...'], but you cannot readily change their beliefs [e.g. 'There is no God because...'].
Ironically, 'to be opinionated' has negative connotations, but 'to believe' in something is often seen as positive [unless in 'blindly believe...']...
Any opinion is an opinion, in my opinion. π