Mixing Angular and Require is tricky. I have an experimental project in GitHub (https://github.com/nikospara/angular-require-lazy) that works in some hacky way. You may take a look as an example.
Opinions comments on this project are also wellcome.
For your errors:
Open a net console (e.g. in Firebug) and check the paths called by RequireJS. Are these paths correct?
Angular modules (in contrast to Require/AMD modules) have dependencies of their own. You must make sure that .js files of Angular modules are loaded after angular. One way to do that is to shim them, e.g. for restangular it would be something like:
shim: {
...
restangular: {
deps: ["underscore", "angular"]
}
}
Otherwise you can load angular and the other scripts with standard <script>
tags, in the correct order.
These are general directions. If you can't find the reason of the problems, maybe you should post some more code; a fiddle/plunkr would also be great, if possible.
Related post in SO: Inject module dynamically, only if required