*Hint* Use less brushes, and more C4Ds. As for blending, the idea is to match the render/stock with the background without impairing the stock's visibility or goofing the flow/depth. I suggest erasing over the render.
Not IMO. The brushing and C4Ds go in different directions. Try to focus on one direction so as they do not converge with each other. The "Arvas" text is a little too hard to read. Make the font size smaller and move the text to the right a bit. You don't have much depth (render looks flat). Render placement is off. I suggest you move it upwards a little bit, and to the left also but not in the middle.
Meh. Your a beginer im guesing. You shouldnt just slap c4ds,brushes, and effects on there. Try and make the signiture go into one direction, creating flow. Also, i reccomend to use stocks because it gives you a backround and its usually blended pretty well. blur the backround of a stock and sharpen the focal ( the person/main point of the picture) this will create depth, making it look 3d almost and more appealing. In case you didnt know, a stock is just a normal picture, a render is a cutout. try using the stock below to make a sig. you might have to decrease the size. Spoiler
Eww, I hate that stock. Anyways, yes, you certaintly have things to work on. I suggest posting in the Sig school thread.