My team idea for 5-man and mythics+

[Xraptorx]

Hi all,

i am thinking of a solid 5 man team for all 5 man dungeons, heroics and mythics. How viable would it be to have 1x prot pally and 4x affliction locks? All of them have self healing as i understand it.

Would i need a separate healer in higher level mythics?

Would a druid tank be better than pally tank?

Do I need a tank or can 5 locks solo the heroics and mythics?

thanks