Your channel trailer is way too long. With these trailers you really want to cut right to the chase. People will decide in pretty short order if they want to subscribe or look at some videos or whatnot...so just tell us flat out what we can expect to see on your channel...what kind of videos you have, etc...cut out all of the fluff...we don't need to get to know you right now. We just need to have our attention caught. Even in one minute we will be able to tell whether we like you...your disposition, your personality...this will all come across within a minute so I'd say really shorten that video up. People have short attention spans, and even shorter when they aren't familiar with a channel or the person who runs the channel.
Also, what others have said about audio/video, etc.
Good luck!