Ive tried following the tutorial video 10+ times now and also tried tinkering with a few settings myself, but every attempt has ended up with hillarious failed results. I get sooo close with my last attempt in the video!

Could someone make a more indepth tutorial video? because i know im not the only one making these silly mistakes! haha.

For no animation - Click on the model (not the game window asset, the asset window), click rig, change from Generic to Humanoid, apply. Should then work fine :)

As for lyring down, I still haven't been able to solve this in 3ds max, or in Unity. The only way i've managed to solve it, is to upload my rigged mesh to Mixamo, and remap everything, then export and put into Unity again.

For invisible, it's usually a mesh that hasn't been added, or texture mistakes - so double check everything

Death animation - I still have no idea what causes this freak out

I know you've solved all I answered, but I wrote it anyway for people who come along to take a peek for the same problems.