1)Not responding to the iqamah: Iqamah is to be responded to just as we respond to adhan.Because it is also a form of adhan.
The prophet said"between the two adhan is the establishment of prayer"(agreed upon)
Ibn Hajar says "the two call means adhan & iqamah"
So going with the general rule from an hadith on adhan "if you hear the muadhin ,say whatever he says"(akhtoohul musoleen, by Muhammad sidiq Al-minshawi,pg 45)

2)saying of "aqamahaallahu was adaamaha(أقامه الله) . people use to say this during the iqamah. This is not legislated. They use this hadith as evidence "Bilal pronounced the iqamah, when he said 'qad qaamati salat' the prophet then say: aqamahallahu wa adamahaa" this hadith is graded weak.(akhatoohul musoleen)

3) The addition of "sayinaa" in iqamah. It is wrong to add this word. "Ash hadu ana SAYIDINAA Muhammada rasul llahi"
Al-shaqeery said "know that it is act of innovation and ignorance to add the word SAYIDINAA and HABEEBINA to the adhan and iqamah" (sunnan wal mubtadi'aat)

Doing iqamah without the permission of the imam is a wrong act.(akhtoohul musoleen,pg47)

doing iqamah and at the same time walking. You will some people,they are not yet in the place of prayer, they will already start doing the iqamah while approaching the place where they want to stand for prayer.
Abdullah bin Ahmad said: I asked my father regarding a man walking while doing iqamah:he said what is apparent to me is that he should make the iqamah while already in his place of prayer(masahil Abdullahi bin Ahmad ,pg 220)

To think that the one who call the adhan must do iqamah. This is a wrong thinking.
The hadith "whoever makes adhan must call the iqamah" is weak (see majmoo,volume 3,pg 111)
The hanafi ,the scholars of kufa,the malikis and many of the scholars of hijaz said 'no difference between the muhadhin and any other person' (deenul khais,volume 2,pg 81)

Loud saying of the takbirarul ihram especially by a latecomer. When the takbiratul ihram of a latecomer is loud, and the imam and those behind him are in sujud,it makes the followers of the imam to think the imam as risen from sujud and some of them may perhaps raise up their heads from sujud.this is a big mistake.
An-Nawawi said: "as for others apart from the imam ,the sunnah is to make the takbeer silently...) (See majmoo ,vol 3,pg 295)
Raising of the voice by the muhadhin and repeating the takbeers said by the imam. This is a common error of our time. It is not legislated.
Sheikhul Islam ibm Taimiyah said 'as for the loud repeating of the words of the imam without a valid reason is an innovation..." Majmoo fatawa ,volume 23, pg 403

saying "Ameen" before or after the imam. This is wrong, it should be done along with the imam.
The prophet said" when the imam say: walaa doolin: say 'aameen'
Sheikh albani said "what is correct is saying it with imam" (tamamul manah,pg 178)

pronouncing 'aameen' than neccesary. Scholars kick against this.it should not be pronounced more than two harakah.and also putting of SHADAH on the meem(م)(akhtohul musoleen,pg 54)
Infact ,Al-mutawlah said 'whoever does so ,his salat is invalid' (al-fatihu ,vol 2 ,pg 265).
This is to show the extent in which scholars kick against this act as it is against the rules of tajweed.

Reciting behind the imam in jahri (loud) salat is another mistake which is common.
The prophet said "He who has an imam ,then the recitation of the imam is recitation for him" (ibn Abi Shaibah)

Not raising the hand up to the the level of the shoulder while making takbir.this a mistake that must be amend. Shoulder level is the least u can go.
"...He will put them (his hands) to the level of the shoulder" (Bukhari)
I believe this piece will be beneficial to Nairaland Ummah, inshallaah.

Copied From Fac. of Administration Muslim Students Association (OAU,Ife) Whatsapp Grp Page.

Good one. Educative. JazakaAllah khyran

May Allah bless you abundantly @Op.
More grease to your elbow as you enlighten the Muslim Ummah.
Some may not the all what you listed until now but you have created an awareness.