On the first, You should work with the flow - The side where goes your sig. On this sig I guess The flow should go to the left, and render place a little more to the right.

(Filter-Blur-Direction Blur could help as a start)
On the second, I'd say that it's the same as your first. Work more on your background, adding a c4d only doesn't look good. You should try working with more c4d, and use the blending option and opacity.
On the third one, Remove the outerglow you put, I don't feel it.

Otherwise, the sig itself look good.
