Magnetic charging

Assuming you mean the MagSafe chargers offered by Apple, while the SE can use them, it will not magnetically attach to them so will need to be placed on a flat surface on the charger.

You an check compatibility here: link-> MagSafe Charger - Apple

Wether it works without removing the case or not, will depend on the case. if its Qi compatible is should work fine without removing it.

The iPhone SE offers wireless charging (works with Qi chargers), but not magnetic.

That depends on the case.

Just give it a try. 😉