第一句应该不能省略as吧,属于固定搭配,第二句as是因为的意思,不构成固定搭配,第二句应该有语病吧,such--as,so--as都是一种强调的意思（...以至于...）,区别在于such后面接的是名词,so后面接的是形容词,知道这个就很容易弄清楚了.
比如 he speak in such a high voice as to be heard out in the street.用so--as的话为
he speak in a voice so high as to be heard out in the street.