Praise be to Allah, and peace and blessings be upon the Messenger of Allah. To proceed:
It is permissible to describe Allah as a "thing" in the sense of informing about Him, because He truly exists. Allah says:
"Say, 'What thing is greatest in testimony?' Say, 'Allah.'"
(Qur'an 6:19)
However, "thing" is not one of Allah's Beautiful Names. Rather, it is a general term that may be used for anything that exists, whether Creator or creation.
No.
The verse speaks about created beings that Allah made in pairs, such as male and female, night and day, land and sea, and other complementary creations.
The purpose of the verse is to demonstrate Allah's perfect power and His absolute oneness, showing that all creation depends on Him. As for the Creator, He is not of the same kind as His creation and is not included in this general statement.
No.
The meaning is that Allah is the Creator of everything that is created. Allah Himself is the Creator and is not created. It is logically impossible for the Creator to have created Himself, because that would require Him to exist and not exist at the same time, which is a contradiction.
Furthermore, if the Creator were Himself created, He would require another creator, and that creator would require yet another, leading to an infinite regress. Therefore, there must ultimately be a First Creator who necessarily exists, and that is Allah, Glorified and Exalted.
Describing Allah as a "thing" simply means that He truly exists. It does not imply that He is created or that He has a spouse. The verses concerning pairs and the creation of all things refer only to created beings, whereas Allah is the One Creator, the One, the Eternal Refuge, "There is nothing like unto Him," and "There is none comparable to Him."
And Allah knows best.