I have ordered the MR816CSX and have a new laptop (MacBook Pro) coming on Friday.

Can I reasonably use the Cubase version packaged with the MR816CSX to get started with small simple recording projects with my band? Or, should I just order Cubase 7 now?

Are you new to recording? If so, you should be able to do basic recording and mixing in the bundled version of Cubase included with the MR816 without missing the advanced features available in the full version very much. Once your experience grows, you will find the advanced features become more important.

yes u can, C7 is not a must for this simple recording