It seems like it should be simple but I just cant figure out how to select the entire project and apply the effect to it.

Load the project file as a clip into a new project using the same project settings.

just curious but couldn't you also group all the clips together holding shift clicking them all, then right click and chose group clips? once they are grouped would the speed video effect apply to all of the grouped clips? can't test this minute but thought i'd throw it out there.

Just tried the group clips and it doesnt seem to work.

You dont seem to be able to apply speed to a project added as a clip into a new project.The clip kinda disappears from the timeline.

Yeah, sorry, momentarily forgot that speed effect is rather special. This technique works in general, however, for other effects. I do not have a recommendation for speed other than to render to something HQ/lossless and then use that as a clip in a new project.