Talk:Vax'ildan/@comment-2602:306:CD59:4870:4154:BED1:1ABC:B8AE-20171017012442/@comment-34493528-20180226011734

Yes, Druids can't wear armor made out of metal. But studded leather armor isn't nessecarily reinforced with metal, it could just be reinforced out of spikes made from a different material. It really just depends on DM discretion. (PHB 144)

Although I'm not sure about the second question. Perhaps the answer is he died from the pain and pressure to his body, and not the lack of oxygen? Although, I'm still not sure on an answer to that one.