It is not allowed during obligatory Prayer (Salah) to add Rokoo' or Sojood because it will invalidate the Salah. Reciting any of the four verses of obligatory Sajda is not allowed in obligatory Salah. If you do Sajda for reciting or listening to any of the four verses of obligatory Sajda, you Salah becomes invalid and you need to perform the Salah again.
Thank you for your question. One of the conditions for a prayer leader according to the School of Ahl al-Bayt (as) is that they are baligh. If they are not baligh, that prayer cannot be lead by them and so if someone participated in that prayer they will need to repeat it.
May you always be successful
congregational prayers are much more better than praying alone. The reward of praying in congregation is many folds more which can be hundreds or thousands of times.
Congregational prayer has conditions including the conditions of the Imam of Jama'at. Woman can lead women only in prayers and she should stand in the first row with other women and not to stand ahead of them.
The main requirements for the Imam of Jama'ah are:
1. He be well versed in the rulings of fiqh and prayer in particular.
2. A man of piety and righteousness, with inner taqwa, high moral standards, and 'adalah, which means he does not commit regular sin.
3. His pronunciation and recitation is accurate.
4. Other things mentioned in the fiqh books.
If there are numerous people who broadly have these main requirements, then the person who is more learnt, or with more taqwa, or better recitation, is presented as the Imam Jama'ah.
And Allah knows best.
According to the verdict of many high caliber scholars, joining the Jum'a Prayer is enough even if you are late and could not listen to the both Khutba of Jum'a.
You do not need to perform Dhuhr.
It is recommended to pray with Muslims from any sect. As it is a Friday prayer, you need to pray your own Dhuhr prayer before or after it.
Praying with our Muslim brothers from any sect is highly recommended.
If it would be within a reasonable range of time after the entering of the prayer time, then yes you can wait, and you will receive the reward of prayer on time, and also jama'ah prayer.
However, if there will be an extensive delay, then it is better that you pray on time, and receive its abundant reward.
And Allah knows best.
It is permissible to perform congregational Prayers keeping the social distancing required by health experts. That distancing will not invalidate the prayer nor the congregation Jama'ah.
This question of the permissible distance in congregational prayers is not new as many think. It has been mentioned in our books before about one thousand years. Shaikh Al-Tousi who established the Hawza of Najaf Ashraf before about one thousand years ago and passed away in 460 Hijri, has mentioned it in his book (Al-Mabsoot). Al-Muhaqqiq Al-Hilli (676 \Hijri) and Yahya ibn Sa'eed (689 Hijri) who were among the prominent Shia Ulama did mention it. The verdict of all these three prominent Ulama and many other Ulama that it is permissible to perform congregational prayer with distance between the individuals as far as the shape of the group is a congregation الهيئة العرفية. This in principle. The medical and health reason based on the the obligation on every Muslim to save himself and other from infection, add another reason to our Maraaji' of Taqleed to act upon the verdict of Shaikh al-Tousi and other old Ulama allowing the distance in congregational prayers.
Yes, some maraja have now come out and are saying that congregational prayers may be held with a certain measurement of distancing between people in the rows.
May Allah grant you success
as salam alaikum
the term "Imam" can be used also for the one who is leading the congregational prayer. In fact he is called "Imam al-Jama'ah".
With prayers for your success.
Imam in Arabic means leader. Leader can be pious like the prophets and their successors mentioned in Quran; (We made them Leaders (Imams) guiding people by Our order.) (Sura Anbiyaa', Verse 73). Leader can be bad person who misleads his followers away from Allah and leads them to hellfire as we read in Quran (And We made them leaders call to the Hell Fire) ( Qasas, Verse 41).
The leader in prayers is called in Arabic Imam al-Jama'ah, while the leader of Friday prayers is called Imam al-Jum'ah.
In some non Arabic languages they call him Pesh Namaz (Leader of prayer).
It also depends on the society as we see in Europe and America, they call him Imam , while in other countries they call him Shaikh or Shaykh. In the Indian subcontinent, Sunni and Shia Muslims use the title of Maulana for religious teachers and leaders of prayers.
Shia Muslims live all over the world and they have their own cultural varieties which is respected in Islam as far as it does not contradict any Islamic teaching.