I've had two WordPress blogs. That was at a time when I was doing almost no online advertising, and until I found time to handle the situation (weeks later), these sites were penalized in the main search engines. They were not eliminated, no matter how the ratings were reduced.
The secure your wordpress website Codex has an outline of what permissions are acceptable. File and directory permissions can be changed through an FTP client or within the page from the web host.
Should your site's server go down for will go with this. You'll make no sales, get no traffic or signups to your site, and in short, you are out of business until you get the website back up again.
In case you ever wish to migrate your site elsewhere, like a new web host, you'd be able to pull this off without a hitch, and also without needing to disturb your old site until the new one was in place and ready to roll.
As I (our untrue address Joe the Hacker) know, people have far too many usernames and passwords to remember. You have got Twitter, Facebook, your online banking, LinkedIn, two blog logins, FTP, internet hosting, etc. accounts that all come with logins and passwords you will need to remember.
But realize that security is something you really need to start thinking about. Do not just be the reactive type, consider steps to begin today protecting yourself. Don't let Joe the Hacker make your life miserable and turn all that you've worked so hard.