What are some ways you can switch back and forth from a static library to a dynamic one? Like if you have the same game engine, what are some defines you could use to switch it on and off as a dynamic or static?

I dont think there are defines because that is a linker command line option, I dont know what the option is on VC++, but I am sure that you can set it on project->options, then look for the link tab, there is a text box where you can add command like options to it, in the VERY remote case that you are using GCC and not VC++ like me, then you just have to add -static to your link options on your makefile, and thats it, I dont know much about make, but I think you can use conditionals, and so . . . all I do is comment out or in the options I want, like debug or release.
hope it was of any help.