Creating a reusable element for my films

Hello all,

My question is: if I create a little title sequence, with video, musich, sound effects, graphics, etc, and want to use it multiple times, is there a way to save that seqence so it can be brought up again in another project?

Or do I have to export that as a finished .mp4 file and then just use that rendered/exported video file?

What happens to quality, if file is rendered out at full HD, but then brought back into a new project and goes through the render/export process again.

Will the quality of that file degrade being rendered out twice? What's the protocol here?

Thanks in advance