Be careful now, don't put yourself in the position of losing ability to administer the blog.
I accidentally lost administrative ability to the blog. What do I do now? How quickly can Blogger re instate me? Help!!!
Having a second administrator for the blog isn't a bad idea, but it comes with a caveat. When you have more than one administrator, either will be able to delete or downgrade either account. Both administrators have to be able to perform the job. Should either account become unavailable, the other has to be able to take over.
Don't assign administrator status to someone who can't do the job, or you don't trust completely.
Remember any administrator will have the power to remove all other administrators (including you) from their status, so don't let a fox into the henhouse.
And, should you have administrator status, and be able to remove yourself because someone else has it too, before you remove yourself note the identity of the other administrator. Don't get into Google Blogger Help, and ask
How do I find out who the other administrator is? I removed myself, and now can't get back in. Help!
Until Blogger fixes this major design weakness, you need to deactivate any administrators who won't be available for an extended amount of time. Decide how long you can, conveniently, wait for the second administrator to perform. If that person will be unavailable for an inconvenient amount of time, deactivate his / her administrative status. Don't depend upon filing a report with Blogger Contact, to get your status restored.
Also, you may need to note that Blogger isn't a robust content management system, that supports and tracks concurrent updates by multiple people. You have to manage the people who update the blog, on your own. You have to be able to trust each blog administrator, as Blogger won't help you track their activity. There is no update log, to tell you who changed something.