Hi Selena!
The sweater pattern has graphs for the bongo drums, music symbols, (and the Mexican dancers too but I didn't use them).
So I just tunisian crocheted the designs instead of knitting. If you don't tunisian crochet, you could probably make the sweater by single stitching and changing colors throughout.
I'm not good at that because you have to constantly flip over your project after each row and read the graph left-right / right-left etc. Plus with the color changes you would have loose ends all over the place in both front and back of your garment that you would have to weave in and hide. But some people are great at that.
Another option would be like you suggested - just making the whole sweater in single crochet with the background color and then cross stitching the design overtop. If it was made in wool and you made it large enough to "felt" by washing it afterwards and drying it in the dryer, the top stitches probably wouldn't be so noticeable as being only stitched over the crochet. But you'd have to be really sure to make it big enough or you might end up having a really awesome doll sweater!

Wool yarn is pretty expensive too so it would be a sad day indeed!
About the skeleton pattern, I found that super cool graph on a graph pattern-making site. I think I listed it in my first post on here. Some talented person made it and it was posted with a lot of other finished graphs from folks. I'm not sure how long the finished graphs are posted on that site before they delete them.
I have found a lot of great graph patterns this way. The people who make them are usually young girls (like teens to twenty-year-olds.) (This is only my guess judging from the subject matter of many of the graphs. For example; rock bands I've never heard of, Twilight-related characters or sayings, video games, anime type characters, popular movies, etc.) There's usually something in the pages of finished graphs for everyone. The graphs can be used for anything you can think of. Cross stitch, needlepoint, or making beaded bracelets. (That's a wonderful art that a lot of people are getting into. Some can be so detailed it's just amazing!)
But since I didn't make the skeleton graph myself, I could never sell it. And who knows where the person who graphed it got the image or idea. They might have taken the skeleton from someone else's design and just made it into a graph for their own personal use.
The Beehive bongo pattern is from probably from the 50's or 60's. I don't think that's old enough to be in public domain yet. Does anyone know about that?