Lol.. well first of all for signatures those are massive..anyways..
1. 5/10 not to be mean but there isnt really anything graphical there.. but lol its funny
2.7/10 the colour scheme is all grayscale.. and once again a bit too big
3.8/10.. lol it would be a 9 if i could read it
but its just a bit too fast (Still love it)
4. 7.5/10 its nice.. and i like the slogan.. but the background is a bit.. ermm.. empty.
5.9.5/10 lol i dont know wtf its about but its cool
Overall: 7.5/10. (i averaged it)
But dont worry im sure you will drastically improve over time.