No, definitely not. Many anime are inspired by various sources. For example, some come from novels, while others are developed independently by animation studios with unique storylines.
Not all anime have a manga counterpart. Some are original creations made specifically for animation.
It varies a lot. Sometimes the anime adaptation can be just as good or even better if the team does a great job. But in some cases, it might not live up to the manga's quality due to constraints or creative choices.
Not really. Many popular series have anime that stay quite close to the manga. Minor differences might exist, but they usually don't change the core of the story.
No way! Anime can be made from all sorts of things. Sometimes they're the brainchild of the animation studio, sometimes they're based on games or other forms of literature. Manga is just one of the many starting points for anime.
Most manga don't make it to anime. It takes a lot for a manga to get picked up for an anime adaptation. Things like having a wide fan base and a story that suits animation production are crucial.
Not all of them. While a significant portion of the Gintama manga has been adapted into anime, there might still be some storylines or arcs that haven't made it to the screen yet.
Not all do. Some anime make significant changes to the story or characters from the manga.
All the poems that appeared in the Cangyue Mirror series and their origins were as follows: In the first volume of the Mirror Series, Breaking the Army, there was a poem from the Tang Dynasty poet Wang Zhihuan's "Climbing the Stork Tower": The white sun is leaning against the mountains, and the Yellow River flows into the sea. I want to see a thousand miles and climb another level. 2 In the second volume of the Mirror Series, the Tower of God, there was a poem from the Tang Dynasty poet Li Bai's "Will Enter the Wine": Life is full of joy, do not let the golden cup empty face the moon. I'm born with talent, I'm sure it'll be useful. Cook sheep, slaughter cattle, and enjoy the party. You must drink three hundred cups at a time. Master Cen, Dan Qiusheng, will not stop drinking. I'll sing a song for you, please listen to it for me. Bells, drums and jade are not worth being expensive. I hope I'll be drunk for a long time and never wake up. Since ancient times, sages and sages have been lonely, only the drinker left his name. In the past, the king of Chen gave a banquet in Pingle to drink ten thousand taels of wine. Why should the host say that there is little money? I must buy it directly and pour it to you. I'll go out and exchange my five-streaked horse for fine wine to relieve my eternal sorrow with you. 3 In the third volume of the Mirror Series, Wasteland, there was a poem from the Tang Dynasty poet Du Fu's Ascending: The wind is strong, the sky is high, the apes howl, the white birds fly back to the clear sand of the mournful island. Endless trees fall and the endless Yangtze River rolls down. I'm always a guest in autumn, sad for thousands of miles. I've been sick for a hundred years, and I'm alone on the stage. I'm in trouble, bitter resentment, frosty hair, downcast hair, I've just stopped drinking. 4. In the fourth volume of the Mirror Series, Sacrifice to the Moon, there was a poem from the Tang Dynasty poet Bai Juyi's "Farewell to the Ancient Grass": The grass on the plain withers and thrives once a year. The wildfire never ends, and the spring breeze blows, it grows again. The far-off fragrance encroaches on the ancient road, the clear green connecting the deserted city. And send the prince away from the luxuriant and full of parting feelings. These four sentences appeared in different volumes of the Mirror Series. They were Cang Yue's citations of ancient Chinese poetry.
The answer is no. Manga has its own creative and narrative style, which can stand alone without the need for a light novel. There are many manga that are based on original concepts and ideas created specifically for the comic format. Some manga may be so unique in their visual storytelling that it would be difficult to translate them into a light novel format. Additionally, the manga industry is vast, and there are many works that are simply not associated with light novels at all.
There can be differences, but they aren't always major. Anime might expand on certain scenes or simplify some parts for better pacing, but the main essence usually stays intact.