The Pope and the filioque are the big ones. Some Orthodox will give you a huge list of differences they think are important but really those are the only two.
I honestly don’t understand what you are saying. We see a whole lot of contention here on many other Catholic teachings. For example, do you say that the following are not important differences?
Purgatory
Indulgences
The difference in Catholicism between mortal and venial sin
The use of statues instead of icons
The Immaculate Conception
Baptism by sprinkling, not triple immersion
Reception of Holy Communion by unleavened bread, without the wine.
The devotion to the Sacred Heart of Jesus
The devotion to the Immaculate Heart of Mary
The shrines at Fatima and Lourdes to Mary
The Roman modern “icons”, so that Mary is pictured in modern terms, not in the traditional Byzantine icon way.
The Catholic teaching on divorce and birth control.
The Catholic teaching that once you are in hell, there is no way anyone can pray you out of it.
The use of guitars, drums, electric organs, clowns, puppets, modern music, dancing, clapping, laughing and swaying to and fro at Catholic Liturgy.
The Catholic use of pagan aborigine traditions, such as sacred smoking, at Catholic Mass.
As in the other thread, you have taken the weird views of people on this forum as representative of the Orthodox Church.
Iconodule is essentially right. Historically, it has been the Papacy and the Filioque and maybe a couple other things.
Some of the things you've listed are obviously not even differences.
Of course, there are many differences. But there are only a handful that have ever caused much contention.
Would it be possible to elaborate on which are the weird views of people on this forum and which are serious differences between the two Churches, in your opinion?
Sure. I'll go down the list.
Purgatory--This is a legitimate point of discussion. Although some here have pointed out the nuances of this issue, I've never met an Orthodox face-to-face who, to my knowledge, believed in Purgatory.
Indulgences--these were formerly sold in the Orthodox Church. The whole Idea seems dumb to me, but that's not the point.
The difference in Catholicism between mortal and venial sin--Most people don't even understand what this distinction is...
The use of statues instead of icons--It's my understanding that statues are not used
instead of icons, i.e. they do not fulfill the same functions. A long time ago I had a discussion with ElijahMaria on whether the veneration of images as such even takes place in Catholicism.
The Immaculate Conception--For many Orthodox, this is certainly perceived as a difference. More subtle thinkers have realized that different perspectives on original sin cloud any attempts to compare this doctrine with any corresponding Orthodox belief.
Baptism by sprinkling, not triple immersion--OK, this is a difference.
Reception of Holy Communion by unleavened bread, without the wine.--Historically, this has definitely been a big deal.
OK, now I think you're starting to get carried away:
The devotion to the Sacred Heart of Jesus, The devotion to the Immaculate Heart of Mary, The shrines at Fatima and Lourdes to MaryAnyone who thinks these sorts of things are a big deal is just not thinking very clearly, or else is way over my head...in RL, I have never, ever heard Orthodox criticize things like this. I'm pretty sure most Orthodox would be uncomfortable with Catholic devotionals, and wouldn't practice them, but this can't reasonably be attributed to doctrine. Prayer practices are, after all, something extremely personal...one typically does not casually try something new, especially borrowing from other religions.
The Roman modern “icons”, so that Mary is pictured in modern terms, not in the traditional Byzantine icon way.--Miss. Lots of icons have been painted in modern styles, especially among the Greeks, even following Western types (e.g. the Western depiction of Christ rising from the tomb vs. the old Eastern image of Him trampling the doors of Hades). These images are treated just like any icon in the OC. Anyone who doesn't acknowledge this fact needs to break out of their bubble.
Frankly, I prefer these images to the New Retro-Byzantine icons, but that's just me.
The Catholic teaching on divorce and birth control.--It's my understanding that at least in some places, there is division among the Orthodox on birth control.
The Catholic teaching that once you are in hell, there is no way anyone can pray you out of it.--Yes, the idea that you can pray people out of hell is weird indeed.
The use of guitars, drums, electric organs, clowns, puppets, modern music, dancing, clapping, laughing and swaying to and fro at Catholic Liturgy.--OK, I am terribly confused about the Clown Masses. Too many conflicting messages. Is it a hoax or not?
The Catholic use of pagan aborigine traditions, such as sacred smoking, at Catholic Mass.--time for a nap.
To take a different approach, you're right that "weird views on the forum" is an exaggeration, but on how many of the above points can you produce serious theological literature?
PS--Orthodox use electric organs too.
PPS--You forgot the Assumption. Orthodox have managed to believe in it and reject it for being Catholic at the same time. Miracles happen.
PPPS--You forgot the calendar, duh! It's probably a more important difference in most people's eyes than anything you mentioned above. I hope you enjoyed Orthodox Palm Sunday...God showed his favor by giving us nice weather...at least here...He always does.