Salaam Sstikstof,
You said: " So many days I'm confused with wether I reject hadith completely or not."
I can relate. I know how hard it is to let go of/reject something you've been propegated to believe sense (perhaps) childhood.
Now I know brother Joseph can speak for himself but, if I may, I would like to say something on his behalf which is that: Brother Joseph is only suggesting that we reject (or rather question) the hadiths on 'thelogical grounds'. In other words, the Quran is the only source/authority for religious guidance and, using it as the sole axiom, all matters in Islam requiring guidance can be deduced directly from it. And, in the words of brother Joseph:
"The Quran claims to be a fully detailed explanation (Arabic: fussilat 41:3; 11:1), the perfect guidance (Arabic: hudan 2:2), a clear convincing proof (Arabic: burhan (4:174), the ultimate scale (Arabic: mizan 42.17; 57:25), the discernment between truth and falsehood (Arabic: Furqan 25:1, 2:53), an evidence absolutely clear (Arabic: bayyina 20:133) and a clear explanation of all matters (Arabic: tibiana lekulli shayin 16:89)."
Therefore, a scripture cannot make those above claims (as made by the Quran) and yet on the other-hand not provide necessary details for human guidance as part of God ordained 'religion', or claimed to be (by some) incomplete, lacking details, and dependent on other/secondary sources.
That said, judging from brother Josephs many articles and Facebook-posts, he is not advocating for an outright rejection of the Hadiths. In fact, as he proclaimed in one of his Facebook post:
"One can make use of extraneous sources for general guidance, best practice, ‘alleged’ sayings of the earliest Muslims, sage sayings, wisdom, to ascertain how the intellectual ancients of the 8th, 9th,10th (etc) centuries CE understood their religion underpinned by the Quran, how these thoughts translated into to practices etc; but are they 'God ordained' in the 'name of religion'? Absolutely not.
And in fact I, myself, have in my personal archives a collection of hadiths which I believe have much wisdom and knowledge to offer, which I try to adhere to as best I can.
Hassan.