Displaying a large and complicated family tree at once is not always possible. Generally speaking, you can always display the ancestors and descendents of any person on the tree, and you can usually display that same information for any siblings of that person.
You can often get what you want, by thoughtfully choosing the person to click on, and changing the options for how many generations of Parents, Children, and Others to show (under the show options link at the bottom of the screen). For instance, if you wanted to show the ancestors of both you and your wife, you could click on your child.
The portion of the tree displayed on the screen will always be the portion printed when you choose print.
There are a couple of ways to print a large family tree in FamilyEcho:
Print the family tree on larger paper (A2 or A0 for example)
Print the family tree on more pieces of paper (change the width and/or height). If you do this, you will probably want a paper cutter to trim the bottom and right sides to make it easier to tape the pieces of paper together.
There are companies that will print out your family tree for you from your GEDCOM file. This resource lists a few of them toward the bottom of the page. Note that your GEDCOM file doesn't include pictures.
I purchased Family Tree Maker just to use their charts. I work in FamilyEcho and then export my GEDCOM file and import it into Family Tree Maker. They have an option where you can print out your whole family tree (subject to the normal limit of how much of a tree you can realistically display at a time) as one large PDF (instead of splitting it into multiple pages. But there is a hard limit with PDFs of a maximum width of 200 inches (about 17 feet), so there are some compromises there as well.
After I had my 3 feet by 17 feet pdf file, I had to find someone to print it for me. If you go this route, I found that blueprintsprinting.com was pretty reasonable at about $45.00. Office Depot and places like that can print that large as well, but they wanted much more money. After it came, I took shipping tape and taped the backside of the family tree so it couldn't rip. I might laminate it eventually, but I figured people would point out errors in this first one.
Note that there are several different family trees in the picture. Even though I could have printed everyone in my particular family tree at once, it would have been much taller and wider. If it was taller and wider, it would either have been smaller and harder to read, or it would have needed to be printed on larger paper, and that would have cost more money (if it would even have been possible, because I was arunning up against the hard 200 inches PDF limit).