Select seams easy and fast way? Is there a way to select seams the easy and fast way? 

I had to subdivide this part with 20 so it would bend well, but now its all black so its impossible to seam. I already zoomed in with DEL (numpad), but that doesnt make it easier to reach tiny parts. Also whenever i zoom in, the object just disappears, so im searching a way that or automatically selects the seams for me or a way where it select a few connecting points at once. 

Pls explain step by step what to do, cause im just a beginner. Thanks for all the help here!
Yes, but working with such a high-poly mesh isn't advisable for a number of reasons.

Instead, consider using a Subsurf modifier. This allows you to work on the mesh in a low-poly state while still getting the nice smooth curves offered by a high-poly mesh:



That said, if you can manage to select one edge with a seam, then you can press &#8679; ShiftG > Seam to select all other seam edges. &#8679; ShiftB for Border Zoom and, if needed, a reduced minimum viewport clipping distance can help immensely with such a task: