Is it still considered a cadence? For example a 1,6,4,b5,1 progression in c major, it might sound wacky but i am just curious if there is a term for it. Also are there cadences for the 2,3,6,7 chords of a key?
This is only a partial answer, as I don't know a term for the b5-I sequence.
As to your second question, there is an answer of sorts: any sequence that ends V or V7-x, where x is anything other than I, is called a Deceptive Cadence, especially in the case of V-vi. A V-ii cadence would sound a wee bit odd, but would still be considered Deceptive, and likewise for the last example you gave, though I must say I hope hope hope I NEVER hear a V-viio sequence!