THExSERGEANT

Try adding the add-ons before starting the world. Go edit world, Go down to  behavior packs and equip each mod you want to be on that world. it will download each mod to the world.

Are you playing vanilla or do you have add-ons/mashup packs on? Ive seen issues with frames with it came to too many add-ons are on the world. 

You can access the bedrock setting in the launcher rather then the website. 

Sounds like a Joy-con drift issue. Nintendo does off a free repair through the website. Have you tried to update the joy-cons? Also you can try to recalibrate the joystick through the settings on the switch itself.

Some enchantments cant be added together. Just like with the bow, it cant have Infinity and Mending together