Tzedokim were people who believed that the mesorah of Torah sheb’al peh was invalid, and that the Rabbanan have no authority.
Modern Orthodox?
I’m Modern Orthodox. I keep the mitzvos, de’oraisa and derabbanan. I keep halacha strictly. I’m not sure what you’re talking about. Unless you think I’m an apikorus, of course. Well, I certainly hope I’m not.
Now, what is an apikorus? The gemara in Sanhedrin 99b gives the following definition: “Rav and Rabi Chanina both said, ‘He is one who degrades a talmid chacham.'” There are some very big talmidei chachamim, gedolei hador, who would consider themselves Modern Orthodox. So just be careful what you say, especially if you’re calling other people “apikorsim.”