You can copy over the midi tracks, by the way. It's only the Wave Files that you need to export.
You can choose Export Tracks with FX disabled to export the tracks you want.
Then import them to the other project with the new sample rate as Chregg describes.
You can export your Pro Channel Settings by clicking the save icon for the pro channels and then opening them in the pro channels for the new projects.
You can drag FX from the old project to the new from the FX Bins, I believe. Give it a try anyway. If that doesn't work, you could drag FX from the FX bins to the Pro Channel FX Bins before saving the Pro Channel.
You can also copy over envelopes.
I believe when you copy over your midi tracks, it will bring tempo changes with it by default.
I'm not sure the best way to get your soft synths from one project to another identically. Perhaps, try this... Make a track template including the midi input and output tracks and import that track template.
(Am I going totally overboard here? I'm not sure what your project actually looks like.).
You might check you copy wave file to new location in preferences before you import the wav files to the new project.
Good luck and happy mixing! I must say I prefer mixing 44.1 files in most cases as well. I can certainly bounce faster, so if it's a band I don't really like...
haha