Usually that's ok, because it's the fonts that often cause problems, especially if the people you're sending it to don't have the same fonts as you. Converting them to outlines guarantees that they'll print the same.
As for the logo, is it a scan, screen grab, photo or saved from a web page? If so, then it's a raster graphic. Although they can be placed in Illustrator, they can't be manipulated in the same way as shapes drawn using Illustrator's tools. Shapes drawn in this way are called vector graphics. Although it's easy to convert a vector graphic to raster, it's not so easy to do the other way around. Most printers will still be able to print the raster images, but sometimes it's not suitable. I'd imagine that the machinery used in many sign writing companies would require vector art.
There are third party tools that can do this conversion for you (Streamline, Sillouette, etc), but the results usually need a bit of work. Personally, I haven't used any of these programs in years, prefering to use Illustrator's drawing tools to manually trace over the image. Once it's done, just hide or delete the raster image underneath.