Can Sharingan copy any element?

The sharingan can copy any jutsu and the rinnegan helps the user to master all seven elements. This works for any jutsu. However, the user must still be physically able to perform that jutsu.

Can the Sharingan copy Fuinjutsu?

A Sharingan user can copy all types of jutsus techniques: ninjutsu, genjutsu and taijutsu.

Can Sasuke’s rinnegan copy jutsu?

Yes and no, unlike the Sharingan the Rinnegan doesn’t seem to have the same copying abilities, but instead has the ability to let the user master any jutsu easily.

Why is Kakashi so good with the Sharingan?

The Sharingan gives you the ability to read the hand-signs, and what ever the person is doing with their chakra inside to make a jutsu work (a jutsu isn’t just its hand signs, after all, otherwise everyone would be equally good with every jutsu). Kakashi’s advantage is his talent/intellect.

Is it possible to copy Haku’s ice mirror jutsu?

It is not possible to copy only when the jutsu combines two elemental types like Haku’s ice mirror uses both water and wind, and Kakashi won’t be able to copy this type of jutsu. you can copy any jutsu so long as hand signs are required but as of late nobody uses hand signs anymore

Is it possible to copy all the jutsu?

You are correct, they can memorize all the jutsu they want but if they lack the chakra affinity it’s useless. I think one can copy any elemental jutsu, but it won’t be very effective if their affinity for that particular element type is very less.

Why don’t people use the Sharingan for copying attacks?

Most people who use the Sharingan don’t use it for copying. If they have it then they’ll most likely use it for genjutsu and to predict the movements of their enemies (this is disregarding things like Izanami, Izanagi, and Mangekyo abilities). People probably choose to not copy attacks often because they aren’t actually able to fully perform them.