You can remove almost any app that will 'let' you remove it. There will be a lot of apps on the device that while you may not want or use them, won't be removable.
When it comes to saving to the SD card, photos, music, videos, etc., can easily be saved to the card. Just change the settings in the individual app you are using for the items (like the camera) to save to the card. However, if you are trying to save apps themselves to the card, that is a whole other scenario. You would need the following for that.
First, you need to be using a phone that is running at least Android "Marshmallow" or be able to upgrade to it. Second, you will need the instructions I am including below. And third, you need a phone that has not been...