So according to you Imamah & Khilafah are one and same thing (i.e. they can be used interchangeably)
In context to the what I said then yes.
So on what basis do people call themselves Imam according to Ahlul Sunnah? For e.g. Imam Abu Hanifa, Imam Shafi, etc?
The problem here is that, you make such foolish arguments, that they put me in a dilemma that whether I should answer such arguments or just ignore them, like i do most of the time, when you argue out of your ignorance, and lack of understanding.
Anyways, I have some free time, so I'll entertain this unworthy arguments. They were spiritual Imams, not political ones. If you read my comment carefully, I clearly stated that the term Imam is quite broad and is used for different position. Even the leader of a prayer in congregation is called Imam. Now your silly argument demands a counter question, on what basis Shia call some people Imam, example Imam Khomeini.
I am talking about verses in Quran mentioning Imamah/Khilafah. Are those titles only restricted to Prophets or can non-Prophets also be appointed by ALLAH (SWT) as Imams and Khalifahs?
For e.g. ALLAH (SWT) appointed Nabi Adam (a.s) and Nabi Dawud (a.s) as Khalifahs of Earth and promised to make Righteous people as Khalifahs of Earth.
If you mean divine appointment, then I disagree with you. These verses you mention are talking about Qadr of Allah. And in this context, every ruler whether good or bad was appointed by Allah.
For example we read in quran:
(It is We Who portion out between them their livelihood in this world, and We raised some of them above others in ranks, so that some may employ others in their work.) (Quran 43:32).
If you are working as a manager in a company, then even that position of authority is given to you
by Allah, but that doesn't mean its divine appointment.
I can quote a lot of Sunni and Shia hadeeth, but I'll keep them for some other time. Let's see some verses of Quran:
THESE VERSES OF QURAN SHOWS THAT DISBELIEVERS WERE MADE KHULAFA(plural of Khalifa).
Said the eminent ones who DISBELIEVED among his people, "Indeed, we see you in foolishness, and indeed, we think you are of the liars."(7:66) [Hud] said, "O my people, there is not foolishness in me, but I am a messenger from the Lord of the worlds." (7:67). I convey to you the messages of my Lord, and I am to you a trustworthy adviser.(7:68). Then do you wonder that there has come to you a reminder from your Lord through a man from among you, that he may warn you? And remember when HE MADE YOU KHULAFA after the people of Noah and increased you in stature extensively. So remember the favors of Allah that you might succeed.(7:69)
Similar can be found when we read the verse where Allah said , He made or appointed Imams who invite to hell fire.
And We appointed them leaders(IMAMS) who invite unto the (Hell) Fire and on the Day of Judgment they shall not be helped.(28:41, Sayyed Abbas Sadr-Ameli).
As for the verse regarding Adam(as) you are referring then, it's actually not a divine appointment rather it mentions the Qadr of Allah. Check out the response of the Angels.
(30. And (remember) when your Lord said to the angels: "Verily, I am going to place (mankind) khalifa on earth. ''
They said: "Will You place therein those who will make mischief therein and shed blood, while we glorify You with praises and thanks and sanctify You. '' He (Allah) said: "I know that which you do not know. '')
The Angels knew very well that Allah was not taking about divinely appointed caliphs/Imams when he said I will make Khalifa on the earth. If Khalifa stood for divinely appointed imams/caliphs then the Angels would have committed blasphemy as per shia belief by asking this question. Because shias preach that Imams were created before the Angels, And the Imams taught Angels how to worship and other deeds. But here we have Angels suggesting that the Imams will do mischief on earth and will shed blood.
And ALLAH (SWT) made Nabi Ibrahim (a.s) as Imam of Mankind and promised Nabi Ibrahim (a.s) to make from his (a.s) progeny Imams of Mankind.
Here it's not in the context of head of state or a ruler, rather its about making them spiritual examples for the mankind, which makes their followership beyond the Ummah they were sent to.
ALLAH (SWT) has mentioned in al-Quran that it is ALLAH (SWT) who gives Kingdom to whomever HE (SWT) likes. How do you interpret this verse?
The same way you interpret this Shia hadeeth.
عنه، عن ابن محبوب، عن إسحاق بن عمار، عن أبي عبدالله عليه السلام قال: إن الله عزوجل أوحى إلى نبي من أنبيائه في مملكة جبار من الجبارين أن ائت هذا الجبار فقل له: إنني لم أستعملك على سفك الدماء واتخاذ الاموال وإنما استعملتك لتكف عني أصوات المظلومين، فاني لم أدع ظلامتهم وإن كانوا كفارا
It is narrated from him (narrator of the Hadith above) from ibn Mahbub from Ishaq ibn ‘Ammar from abu ‘Abd Allah(as), who has said the following: “Allah, sent revelations to one of His prophets who lived in the time of an oppressive and tyrannical ruler. It said, ‘Tell this tyrant, “
I have not given you this opportunity to shed blood and seize properties. I have given you this opportunity only that you hold back the voices of the oppressed from coming to Me. I will not allow any oppression without justice being served, even though they (the oppressed) might be unbelievers.’” (Al-Kafi, vol 2, page 334, H 2649, CH 132, h 14; Majlisi graded it as Muwathaq(reliable) in Miraat ul uqool, vol 10, page 303]