im extremely surprised you are having trouble with the unit. i have been running lowrance units for 8 years on multiple craft and have always found them some of the most user-friendly. from the big HDS multi-use head units down to the little elite series. im not as familiar with the elite 4 series, but the systems should be basically the same.
the reason you dont see a little picture of a 'fish' or an 'arc' is basically because this is a 21st century machine. the DSI imaging should show as accurate picture of an actual fish, as can be seen. (the 4" screen and 320x240 res are big factors, though).
a school of bait should--in the best conditions, look like individual fish, and your large fish--trout or whatever it was, should look as much like a trout as possible. but, just as with any electronics, the best images are something to reach for, and may not be the every day results. i hate to say it, but it is the truth. the more time you spend with the unit, the more you will learn to 'read' the images. if you just want little fish pictures, you do indeed have a macbook air, when you wanted an etchasketch.
as far as firmware updates, check http://www.lowrance.com/en-US/Software- ... re-Update/
from time to time.