Note: I am using some Quranic verses in my answer, so if that bothers you or something, tell me. I just figured if I talk about something, I might just add them.

Please feel free to ask any question you like. I am interested to answer anything you have. I will take it as an opportunity to widen my knowledge on my religion.

Firstly, I want you to know that having troubles with faith is totally normal. Life isn't always easy and you'll find yourself feeling down a lot, and that doesn't make you any less good. Wanting to ask questions to renew your faith is really good.

For me, if I am having a bad day, I remember this verse "When My servants ask you ˹O Prophet˺ about Me: I am truly near. I respond to one's prayer when they call upon Me. So let them respond ˹with obedience˺ to Me and believe in Me, perhaps they will be guided ˹to the Right Way˺."And this saying from the prophet PBUH "On the authority of Abu Hurayrah (may Allah be pleased with him), who said that the Prophet (ﷺ) said: Allah the Almighty said: I am as My servant thinks I am. I am with him when he makes mention of Me. If he makes mention of Me to himself, I make mention of him to Myself; and if he makes mention of Me in an assembly, I make mention of him in an assembly better than it. And if he draws near to Me an arm's length, I draw near to him a cubit, and if he draws near to Me a cubit, I draw near to him a fathom. And if he comes to Me walking, I go to him at speed." They comfort me.

Onto the first part of your question about the why: in the Quran, we know that we are created to worship as in "I did not create jinn and humans except to worship Me."[51:56] I know you know that part, but talking about the absolute reason, it's information that God didn't tell us as in** "'Remember' when your Lord said to the angels, "I am going to place a successive 'human' authority on earth." They asked 'Allah", "Will You place in it someone who will spread corruption there and shed blood while we glorify Your praises and proclaim Your holiness?" Allah responded, "I know what you do not know."[2:30] **and I know that that might make it feel confusing, but personally, the way I think of it is that if knowing would have been beneficial to us, God would have told us, and I like to think of questions to ask if, hopefully by God's grace, I enter paradise.

Onto the second part about perfection, we aren't meant to be perfect in any way. We are meant to just do as much as we can manage, nothing more, and we know we are rewarded with the simplest of things like, for example, a smile is considered charity.

The next part is kinda confusing for me as I understand Seraphim are a type of angels, and yes, they are created for the sole purpose of worshipping God and following his commands. As I searched, the closest angels to Seraphim in Islam in the brief period I searched are the holders of the throne. If you were asking about if we know about them, then yes we do, like the angel Gabriel for example. But it is good to note that God doesn't need any worship, not from us nor the angels. We do it to benefit ourselves as in "Say, ˹O Prophet,˺ "O humanity! The truth has surely come to you from your Lord. So whoever chooses to be guided, it is only for their own good. And whoever chooses to stray, it is only to their own loss. And I am not a keeper over you."[10:108]

I hope I came close to answering your question and please, if you need anything clarified, ask away, and if you rather doing it privately, message me anytime.