Will I lose all my scheduled jobs when upgrading to the latest version?

Version 7 and 8 are different applications. You can have both installed on your machine and run them side by side. When installing the version 8 client and server, you will need to build a new cluster and connect to the Centerprise 8 server. You will still be able to use version 7, so nothing will be overwritten. Also, all your models and flows created in Centerprise v7 will work in v8.