Something that has been on my mind lately

So for Echidna's contract, I think Subaru, after he knew her motives, should have just done this:

Accept the contract, which was Echidna looking into his life, even the RBD, and in return, he can enter her world, communicate with her even outside the dream world, and seek her advice;

he should have accepted it, and not rely on it but rather improvise it.

Meaning if Echidna told him to do a thing, he will not do what she said exactly, but use it in his own way, and ask her about things that no one would normally know, such as how to awaken a Gluttony victim - basically use her knowledge, not as a source of guidance, but as a base, that way, it'll make his life way easier. in fact, I bet she'd have been SO useful in arc 7, where he was alone relying on himself clueless about the empire. (Unfortunately, it's been like 1 year since I read it so I can't give clear example or specific moments, but I am sure as hell she'd been useful in the gladiator arena, not to mention helping him in strategizing.)

Ofc, this thinking isn't possible for Subaru to consider because he despises witches and he'd rather rely on himself, but I sure as hell wouldn't throw the chance to have the manifestation of knowledge as a Tax advisor in a foreign world, which she had lived in for 400 years+ at the cost of just prying onto my life, and precisely because she's a witch with no emotions, I wouldn't careless about her prying at all, especially she HAS to help with genuine will due to the contract. Even if she tries to manipulate me, she has to nonetheless still advise me and I'd see through her manipulation because the contract will make it hard for her to lie.