Edit a video testimonial (combine 3 <1min videos, add graphics, resolve sound issues)

I have 3 short videos which we'd like edited into one video testimonial which will be used online. The videos are viewable on YouTube, however I can provide the original files in .mov format.

VIDEO-1: 2014-09-23 13.06.30, DURATION: 1:02 min, YOUTUBE URL: http://youtu.be/LqZx67gKUHQ
VIDEO-2: 2014-09-23 13.07.32, DURATION: 0:56 min, YOUTUBE URL: http://youtu.be/K-1IDaGIfEw
VIDOE-3: 2014-09-23 13.08.39, DURATION: 0:58 min, YOUTUBE URL: http://youtu.be/FazgIpbRbZo

As you will see if you watch the videos above, all 3 have sound issues (low level, some background noise) which we would like resolved as much as possible (please provide feedback on whether you think this will be possible and to what standard).

In addition to resolving the sound issues and combining the three videos into one I would like an idea of what to do with the fact that the right hand side of the frame is empty. (i.e. should we crop the video or should we add some graphics into here?)

I envisage the final video running as follows (although I am open to suggestions on improvements)

> Some on-screen text to appear as an intro to give the whole thing some context.
> VIDEO-1 (The name and job title of the person speaking to be displayed onscreen, along with their company logo)
> The 'question' displayed as on-screen text to intro video 2
> VIDEO-2
> The 'question' displayed as on-screen text to intro video 3
> VIDEO-3
> A final splash screen with my company name, logo and contact details

The finished video needs to be in a format that we can upload to YouTube.

Time is of the essence - I need to receive the finished video file before Sunday the 23rd!