Climbing is definitely planned though I am not sure how I do it, probably holding the jump button while jumping against a wall to pull yourself up, crouching and sneaking are the same thing, crawling makes you less visible too like sneaking and you can get into tighter spaces.
All 3 of those exist in recent Minecraft Vanilla Versions by the way, climbing is like with ladders basically, sneaking exists since ages, and crawling can be achieved by being squished though a trapdoor somehow.
As for the Camera View, it is still first person ofcourse, basically a Minecraft Clone of sorts but with some significant changes and improvements, which i mentioned before. 
(With the Diagonal directions I meant more the Walking Vector, not a top down perspective)