There's no easy way to write these scripts, but I highly recommend that you write post-deploy scripts and include them in your project so when the project is pushed, everyone gets those changes. More importantly, they should be there so the changes will be released when you publish your project. You'll need to write them in such a manner that they can be repeated (if not exists ... insert type commands).
You can definitely backup and restore the shared database regularly as long as you know you've got the local changes checked in. Nothing is worse than losing a bunch of work because you've restored over your database.
You can use the "Data Compare" option under the SQL menu as well, but you want to understand what you're doing before just running it or you'll likely experience data loss.