I am replacing a former employee who has his personal account listed as being the owner of most of the jobs in in the Agent. Before I move forward with replacing his login with that of a service account, I just wanted to be sure that the following is true.
For non T-SQL jobs, the job executes under the Windows privileges of the account which owns the SQL Agent process (an account which is required to be in the sysadmin role within SQL Server). Unless you're using a proxy, this is true no matter who the owner of the job is. So, since we're not using proxies, no matter who I make the owner on these non T-SQL jobs, nothing should fail as a result.
And since this former employee was a sysadmin, for the T-SQL jobs he owns I either need to make the new owner also an account in the sysadmin role, or, I need to setup an account with permissions to the items being accessed in the T-SQL code being executed directly by the scheduler.