Sayyed Muhammad Husaini Ragheb

Salam
Read it comprehensively here:
https://en.wikishia.net/view/Marriage_of_Umm_Kulthum_with_%27Umar_b._al-...

You don't have to inform her. 

Unless the woman with whom you want to engage in temporary marriage is a Christian or Jew and you have a permanent or temporary Muslim wife. In such a case according to Sayyed Sistani you have to take your Muslim wife's consent. 

In general the Shia jurisprudential ruling is that a Muslim can marry any other Muslim as long as they are Muslims (except a Naasibi who shows enmity towards Ahlul Bait a.s).

This means that a Shia(male or female) can marry a Sunni, however the condition is that the Shia is able to preserve their Shia belief and be free to practice their Shia belief and not be negatively influenced by their partner. As for a Salafi in general, they have a strong tendency against the Shia in which case things could come to surface during the relationship which could make it difficult for the Shia spouse. 

In a nutshell, due to extreme possibility of perversion from the right path of Ahlul Bait a.s. in such a case for the Shia woman, the well known scholars won't permit such a marriage unless she finds herself so firm in beliefs and knows for sure that she won't change.

Assalamu Alaikum Wa Rahmatullah 

NO. 

Sayyed or Sayyeda is an Arabic honorific title denoting descendants of prophet Muhammad (s.a.w.a). According to fiqh, it is a title given to the descendants of Hashim b. Abd Manaf (the Prophet's great grandfather).

So all the people from the bloodline of Hashim ibn Abd Manaf are Sayyeds or Hashemites. So is Hazrat Abbas may Allah's peace and blessings be upon him and raise us all with him. Ameen

Assalamu Alaikum wa Rahmatullah
according to narrations we have many advice regarding wearing the rings on the right hand, one of which is the famous hadith in which we read about the Ziarat of arbaeen.
These recommendations are apparently for the recommended stones like Aqeeq and those on which there is a Zikr.
On the other hand we have disrecommendations regarding wearing them on the left hand which you know is usually used for Istinjaa(purifying the body)
So as a conclusion we can say that there is no recommendation or disrecommendation with regards to the marriage rings nowadays unless they have recommended stones on them like Aqeeq of Yemen or they have Zikr on them.

Assalamu Alaikum Wa Rahmatullah
The Ghusl is valid but he has done a sin letting the prayer become Qadha.

Assalamu Alaikum Wa Rahmatullah
After reciting Surah al-Ikhlaas(Tawheed).
Knowing that this Surah contains very profound attributes of Allah swt, it is quoted that Imam Baqer(a.s) used to recite this Zikr after this Surah which literally means "My Lord is like that" and because of this hadith scholars have said that it is Mustahab to say it once or 3 times after reading Surah Tawheed.
Note that the one who recites the Surah should say this sentence i.e. in Furada prayer, one who recites the surah would say that and in congregational prayer the Imam would say it and not the followers.

Assalamu Alaikum Wa Rahmatullah
No one actually knows about this except Allah swt.
What matters is that you remember your deceased ones by reciting Quran for them and praying for their souls and to give charity and gift the reward to them because now they have no access to good deeds except someone does for them.
It actually does remind us how empty handed we ourselves will be in the next abode and motivates us to gain more for our next life.

What reward does the Almighty bestow upon Imam Hussain that is both befitting to his sufferings and reflects the justice, generosity, and mercy of God? Based on this, God has granted him many rewards, one of which is the honor and grandeur in this world to the extent that encourages and motivates all people to visit the sacred shrine of Imam Hussain and promises great rewards to the visitors. One of these divine promises is a hadith that Sheikh Mufid and others have repeatedly narrated. Imam Ja'far al-Sadiq said: "... And whoever visits the grave of Imam Hussain on the day of Ashura is as if meeting God on His throne." Of course, this is not strange, as we have similar narrations regarding visiting the Prophet's grave as well. Imam Ja'far al-Sadiq said: "Whoever visits the Messenger of God is as if meeting God on His throne." Imam Ridā said about the significance of visiting God: Since visiting Him is not possible, God has equated visiting the Prophet as visiting Himself. It should be noted that visiting Imam Hussain keeps alive the lofty goals of that noble Imam, which is indeed to safeguard the religion of God and the commandments of the Quran.

Unintentional vomiting doesn't invalidate the fasting

if you touch the unwashed dead body with the wet hand then your hand becomes Najis so if you touch another thing with that hand while it is wet that thing will become najis too.
But touching the dead body with dry hand doesn't make your hand najis and the only duty is to perform Mayyit touching Ghusl.

Satan was not created a Satan as he is now with the devilish power. For many years he was a companion and associate of the the angels. He misused his position and power, and began to rebel against goodness and truth, and started doing wrong and evil and finally turned to what it is now. On the other hand; SATAN can systematically not harm or seduce a

believer unless he is obeyed. As for those who wish to tread the path of truth SATAN is a means of manifesting, and bringing to action the possibilities and hidden power of man; for evolution always establishes through contraction and conflicts.

So creation of Satan as a Jinn who used to worship Allah for a long time before creation of Adam has nothing to do with Injustice.