I live in Paso Robles, California.
The transducer you had for the LCX 332c is the same one you would use for the HDS 9 Touch. The string of bubbles you describe with the half arch is exactly what you should see. If you have another unit on while you have the touch unit on, then you will get vertical lines as interference. Any small dark blue dots which can clutter the screen is normal "stuff" to have on the screen.
If you are not seeing any arches, then there probably not any fish under you. Everything sounds right. If you want to eliminate the clutter you can turn down the sensitivity a little and it will go away. When you do this you will be eliminating any small baitfish that you may go over also so I find it better to look "through" any clutter I see on the screen. More time getting used to what you are seeing and learning to interpret those images is the best advise I can give you.