From what I gathered so far yes its a form of extreme catholic beliefs
Um, no, it is not an “form of extreme catholic beliefs.” It is a personal prelature (a canonical designation) that is Catholic. If one were going to apply an adjective, it would be “orthodox.” Not “extreme.” Orthodox meaning “no heresy.” Their founder is a Catholic Saint.
that one apparently can earn to be come a saint, thus avoiding purgatory and going straight to heaven
(1) There is no teaching in the Catholic faith or in Opus Dei’s spirituality regarding earning anything. Grace is a free and unmerited gift.
(2) As for whether one will undergo purgation prior to entering Heaven, the Church teaches it is certainly possible. Nothing uniquely Opus Dei there. The Church grants plenary indulgences, and certainly the Bible and the Church call us to perfection, call us to holiness. That is, after all, what Sainthood means-- they are the holy ones. This teaching is neither new, nor novel, and certainly not something that is out of step with Catholic teaching. If Opus Dei is teaching that we can-- and should-- all strive to become Saints then, well, they are rather Pauline in that regard as St. Paul taught the same thing.
this is achieved by denouncing everything that affects your relationship with God.
And did not Christ teach the same thing?
So far, what you have described is (a) Christ’s preaching in the Gospel and (b) Paul’s preaching in his epistles.
My GF tried it out for a while she told me, and she didn’t want to continue as they basically wanted her to be cut out sort of speak from the world
We are called to be in the world, but not of the world. St. JoseMarie was a very scholarly saint who knew his scriptures.
she also mentioned you need to do what they call “mortifications” where one must punish one self,
St. Paul speaks in his epistles about mortification. And, he physically mortified himself. And, he urges us to do so too.
An acquaintance of mine in Opus Dei practices mortification-- he sometimes drinks his coffee without sugar (the bitterness reminding him of Christ’s sacrifice) and as another mortification he often works 5-10 minutes into his lunch time at work instead of taking the full hour and offers up that time as a mortification.
Big, scary stuff there… not.
this to me is sounding what budhist believe in “nirvana”
Sounds to me like you completely misunderstand Catholic teaching if you believe that the Church (or St. Paul for that matter) taught anything resembling Buddhism.