There is a basic canon of Torah that is different than the Christian canon. The basic Torah cannon includes the written Torah which we have together with Christians but also the Oral Law which Christians don't accept.
But the Torah cannon is not fluid. You can't just write a book in Hebrew about Torah topics and say it is a part of the Oral Law.--even though people do this all the time. The reason they do this is the basic Torah cannon is hard to read. It is not light literature. And it is hard to understand. And it is against worship of people. If some person has  a particular figure he admires and he wants to worship him or her, they add some book or series of books that  make worship of that person to be considered kosher and desirable.

1) The Torah cannon is the regular "Tenach" (Old Testament), the two Talmuds, Mechilta, Sifra, Sifri, Tosephta, Torah Cohanim, Midrash Raba. It is  lot to read, but you could go through it in a year or two.  When you add the commentaries, it takes more time.
2) The Torah cannon also is different in the weight given to each section. The Oral Law is not given the same weight as the Written Law. We know it is just human beings trying to understand the Divine wisdom of Torah. But it has more weight that just anyone's opinion.
3) Halacha literature has a funny kind of status. Because it tends to stick with the Oral Law it partakes in some aspect of the respect we have for the Oral Law. It at least has the advantage that it is understandable. You don't need to spend two weeks on one page as you do when you study Talmud. But it has the disadvantage that it is not in fact the Oral Law. It is just someones opinion of what the oral law would say about some issue.
4) Kabalah also has a funny kind of status. It is not the Oral Law. But some people think it was handed down in some kind of secret tradition. Even so, it is not the Oral Law. It is, at best, a possible addition.
5) Shelomo Luria had a few choice words about the Rambam. Let's say he did not like the idea of anyone trying to rewrite the Oral Law--even someone of the stature of the Rambam. Nowadays the divorce between halacha and the Talmud is complete.  People that follow halacha don't know nor care what the Talmud says. And the modern Halacha books of the Charedi world are perversions of halacha as understood by the Talmud--even those of Rav Ovadia Joseph. Certainly Reb Ovadia did not intend this but the simplifications he introduced into a halacha are definite perversions.
E.g. you can crack nuts on Shabat and put the shells on the table. To say otherwise is a perversion of halacha. You can't make a pile. So what you have is people supposedly trying to make halacha simple but what they end up doing is distorting it into Picasso portraits.
And in fact even this is being stricter than you really have to be. Because that Mishna (Chapter Beit Shamai in Shabat where this issue comes from) is Beit Shamai--the Gemara reversed the order right there. The opinion of Beit Hillel right there is even shells of nuts that you can't eat are not mukza. [That is Rashi's opinion there on the page.] And that is  Stam Mishna (a mishna with no names) [Beit Hill and Beit Shamai is considered "stam"] coming after an argument and the Halacha is like Stam, Not to mention Rabbi Shimon Ben Yochai who does not hold by mutza at all except for things that are not fit for any use and which one put away like figs on a roof to dry.[The halacha is in far like Rabbi Shimon, but the Talmud itself does state cases in which R. Shimon would agree there is muktza --so I am not using his opinion here to find a permission. I am just mentioning it as another factor to add to the role call.] And if you look at the reason for muktzah the Raavad brings, the reason for it don't apply when there is no public domain around. [600,000.]
So I am not saying Reb Ovadia is not right. Rather it is possible to simplify halacha without perverting it. Halacha today means taking the most strict opinion and making it stricter (in the name of making it "simple") and then presenting it as an unquestionable immutable law given at Mount Sinai.

So fine that Reb Ovadia wants to say that shells are muktza. Fine, he has plenty of support. All I am saying is when people write in his name not to peel the shells and put them on the table that is plainly false. And even the shells --it is not to everyone that they are mukza. What if not everyone wants to be strict?  But strict or not is not even the issue. It is the fact that the Talmud is considered irrelevant to this discussion. No one would even dream of opening up  a Gemara to discover a halacha. That is what I mean to say when I say the Halacha has been divorced from the Oral Law.