My thoughts on RAID may not be all that helpful since I run Windows and Linux systems, but I generally eschew RAID systems on the grounds that added complexity equals added problems and my brief experience with RAID proved that to be true.
Oh and how long to you save your project after you've given a finished copy to the bride and groom?
This is a very important question with potential legal repercussions. It is connected to the questions of how much influence your client has on editing and when is the timeline crossed after which they can no longer expect to request changes.
Both these should be spelled out clearly in your written agreement (for sales purposes, we do not call it a "contract").
Our agreement states that clients generally give us full discretion on editing, but they are allowed to request changes that take up to one hour of editing time. Then we spell out a timeline by saying that we will send them an "approval copy" after which they have one week (or is it ten days? I forget.) to request, in writing, specific changes, if any, to be made. Any changes that require more than one hour of editing will be billed at our editing hourly rate.
This has only happened once and when I sent my email reply with time estimates for each change, the client merely chose the changes that allowed staying within the one hour limit. About sixty percent of the time, clients approve the video without changes. Of the other forty percent, most changes involve misspellings in the credits (which we only copy-paste from our web form where the client has typed the credits!) or a change of music (when the client had failed to enter a list of prefered titles) or sometimes removing or reducing a specific person's appearances in the video.
It is made clear that if the time limit passes without a written request of changes being received, then the video is cast in stone and no future changes can be expected.
This arrangement seems (to me) fair to both client and videographer. Everyone knows what is possible and how much time is allowed. This system has worked beautifully for me for many years. The important thing is to have all possibilities covered in WRITING in your agreement and to have time limits on every possibility.
I suppose it wouldn't be too much trouble to save everything back out to tape, but all we do, archival-wise, is save a copy of each dvd and all original tapes. Even this has been rather superfluous because only on two occasions have we been asked for another copy. In one case they wanted to give out more copies to relatives (a year later) and in the other case, they had only kept a single copy for themselves and it got damaged (five years later). While I was happy to be able to oblige, our collection (especially of tapes) has just gotten out of hand and we are now starting to discard all tapes more than five years old.
