Prepare a CSV File to Import New Exchange Online Users:
http://help.outlook.com/en-us/140/ee441218.aspx#required

You can refer to the steps below to bulk remove the users:
1.Create a CSV file that contains all the users you want to remove:
The CSV file should include the five required attributes: Name, EmailAddress, FirstName, LastName, Password.

2.Install and Configure Windows PowerShell
  http://help.outlook.com/en-us/140/cc952756.aspx
3.Connect Windows PowerShell to the Service
  http://help.outlook.com/en-us/140/cc952755.aspx
4.Run the command below:
$users =Import-Csv C:\Users\...\Desktop\Password.csv
$users | ForEach-Object {Remove-Mailbox –Identity $_.EmailAddress}

Note : You should find the path of the CSV file, and use the path instead of C:\Users\...\Desktop\.

By default, the Refinement Web Part doesn't show refiner counts — that is, the number of results for each refiner value.

For example, if you've enabled the managed property Color as a refiner, the refiner values will be colors, such as Red, Green, and Blue.

You can add refiner counts by changing a value in an HTML file so that the refiner values are shown as Red (10), Green (12), and Blue (8).

1. On the page that contains the Refinement Web Part, on the Settings menu, click Site Settings.
2. On the Site Settings page, in the Web Designer Galleries section, click Master pages and page layouts.
3. On the Master Page Gallery page, click Display Templates.
4. On the Display Templates page, click Filters.
5. Open the Filter_Default.html file.
6. Change the value for ShowCounts to true.
7. Save the file.

You will need third party solution if your Multi-Function Printer (MFP) does not support scanning capability to Office365.

There is actually another option, which is to use the Mapped Drive to scan/upload the content to Office365.

You can map a drive letter on your desktop to the SharePoint Online site where you would like the scanned image to be saved. 

How to configure and to troubleshoot mapped network drives that connect to SharePoint Online sites in Office 365 for enterprises

Yammer integrates with SharePoint via Web Parts. Yammer maximizes the power of SharePoint and turn business communication into a social, mobile, and engaging experience.  Yammer adds a highly secure, real-time social layer to SharePoint that drives user engagement.

You can get the Web Parts from Yammer website.

http://success.yammer.com/integrations/sharepoint/

Security planning for SharePoint 2013 farms

Plan security hardening for SharePoint 2013