Brother, I would like to believe that Shia/Sunni divide does not factor in Iran's equation but the facts speak for themselves.
In your previous post you mentioned how Iran has pacts with Syria, Iraq and Hizbullah. All three of the countries or groups you mentioned are Shia controlled. This is not just by accident my Brother.
I think Iran's interest in Syria is because of Alawite rulers ( Alawites are a branch of Shia Islam ), if the Sunni majority of Syria gets rid of Assad, Iran may lose interest in Syria. Iran's interest in Iraq is because Shias are the rulers of Iraq (Nuri Al Maliki) and Hizbullah connection is because of their Shia connection.
Iran should not be leaning towards countries or groups of Shia faith ONLY. Sure it is natural for Iran to have close ties with their Shia brethren, but not exclusively with Shias ONLY. You are our Muslim Brothers and we are followers of the same Prophet (PBUH) and believe in same Quran. I think Sunni and Shia Muslims should support and defend each other because we are part of the same family.
You have one problem with your post:
These are most 'Sunni' states who reject Iran and even hate it.We shake hands with everyone who accept us.
Before Syrian crisis,we had very good relations with Qatar.We have good relations with UAE ,Kuwait,Pakistan and Oman.
These is not accidental.
But on the other side,Sunni countries like KSA,Qatar and Turkey send foreign mercenaries to Syria because its ruler doesn't follow their sect.They destabilize Iraq,send terrorist suicide bombers to the country to murder Shias,because it's PM is not a Sunni.They support international sanctions on Iran and they try to bash Hezbollah in the first chance they get,even if it means siding with Israel.
What is this supposed to mean?Wasn't Iran among the first countries who recognized and supported Egyptian, Libyan and Tunisian revolutions?Aren't all of them 'Sunni' countries?So,isn't it natural for Iran to be closer to Shias?About the Syria case,it's a matter of national security,but Iran also has always supported talks and dialogue between opposition and government,it even held a conference in Tehran with opposition figures.
The whole Arab Sunnis funded Iraq to destroy Iran,so if we don't send flowers for them,pardon us.
I'm not generalizing though,there are Sunni majority countries who are our brothers.Like Pakistan.Even though majority of its population is Sunni,but I don't see Pakistanis hate spreading about Iran only because it's a Shia state.Unlike most Arabs,they are not obsessed with sects.The same goes to Iranians,You can barely find any Iranian member who insults Sunnis and their belief,they may agree with them ror not about some matters,but at the end,they are all Muslims.
Now you can search a little bit,even on this site about the insults to Shias,actually I'm used to see 1 or 2 of them everyday.
I hope at the end,people stop this Shia/Sunni bs war,but unfortunately,as long as there are idiots in the world,this will continue.