If i want to render to a texture in opengl 3+ can i uses the same vertex shader and fragment shader that I use to handle other regular loaded textures or do i need to create a separate vertex shader and fragment shader just for the handling of the frambuffer texture?

It shouldn't matter whether the texture was/is attached to a fbo at any point. Just don't render to a texture you are currently sampling from :)

Yes, you can use same fragment and vertex shaders for your framebuffer texture as well as for your rendering you main scene objects/textures.