All features are listed under functions. You can also view many features in action in videos hosted on the //SEIBERT/MEDIA YouTube channel.

No, not directly. 
You can notify other users with the @ mention. They will be notified by email and in their Confluence inbox with a link to the post.

Yes! 

Users with these projects/teams need to have the appropriate permissions for the respective spaces, and microblog timelines need to be embedded in the spaces.

So that the content of the post or the discussion about it is not made unintelligible because of a missing comment, the last or most recent comment must first be deleted. If there are no comments on a post, the post can be deleted immediately. When comments exist, they must be deleted before the post can be completely deleted.

Normal users can delete only their own posts and comments. That means, they cannot delete their own posts when others have commented on them. The other users must first delete their comments. Administrators can delete their own and others' comments and posts (but still following the order of deletion as described above).

No!
At the moment, it is not possible to restore deleted posts.

The microblog is particularly useful when providing up-to-date information quickly, to a large number of users.
Longer posts are better suited to pages or blogs, but when these are important, you can write a microblog post and link to the important pages/posts.
Videos or pictures can be sent quickly and easily via the microblog to other users. With our microblogging use cases, we've provided many useful examples on how to use the microblog effectively.

Pictures or other attachments that you upload are directly attached to the microblog post in the space where the microblog resides.
The attachments are not attached to any page, e.g. to the homepage of the space, to avoid long loading times.
You can download attachments directly from the microblog post.
Alternatively, you can search for attachments, or as an administrator, go to the the space configuration under Contents, where you can see the attachments and, for example, their keywords.

When a post has been changed, the date changes to that of the last edit, and the link "Edited" appears.
Clicking on "Edited" will show you the history of the post and its tracked changes.

Yes!
You can use the microblog in as many spaces as you like, create an infinite number of topics and posts.

However, it is not possible to include two microblog timelines on one page. If you have a situation where this would be useful, please contact us. We are always interested to learn about new scenarios and would love to take them into consideration.

Yes, to an extent!

Because the microblog is tied to the Confluence spaces, you can use the users' space permissions to restrict the microblog to a space.
In the global Confluence Administration under Microblog → Set permissions, you can determine what permissions are sufficient for a user to post and respond to this space's microblog and its sub-topics.
When a user has the Add Page, Add Comments, or Add News permissions, they can create microposts.
However, normal users can delete only their own posts or comments. Administrators can delete posts and comments from other users.
When a user has access to the microblog of an area, they must also be able to revoke user permissions for the respective space. It is not possible to restrict users' access to individual topics.

No! 

A character limit is currently not available and is not planned. Each user can decide how much or little they write.
As an administrator, however, you can specify how many posts and comments are displayed in a microblog timeline before a button for loading older posts and comments appears.
We plan to limit the height of any single contribution using a "Read more" button in a future version.

Stacktrace

in atlassian-confluence.log

ERROR [ThreadPoolAsyncTaskExecutor::Thread 24] [plugin.osgi.factory.OsgiPlugin:239] (onPluginContainerFailed)> Unable to start the plugin container for plugin 'net.seibertmedia.plugin.confluence.microblog'
 -- url: /rest/plugins/1.0/ | referer: http://localhost:8090/plugins/servlet/upm | userName: admin
java.lang.NoClassDefFoundError: com/atlassian/hipchat/api/cards/Card$HtmlActivity
	at java.lang.Class.getDeclaredConstructors0(Native Method)
	at java.lang.Class.privateGetDeclaredConstructors(Class.java:2671)
	at java.lang.Class.getConstructors(Class.java:1651)
	at org.springframework.beans.factory.support.AbstractBeanDefinition.getResolvedAutowireMode(AbstractBeanDefinition.java:517)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1044)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
	at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:772)
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:838)
	at org.eclipse.gemini.blueprint.context.support.AbstractDelegatedExecutionApplicationContext.access$1600(AbstractDelegatedExecutionApplicationContext.java:60)
	at org.eclipse.gemini.blueprint.context.support.AbstractDelegatedExecutionApplicationContext$4.run(AbstractDelegatedExecutionApplicationContext.java:325)
	at org.eclipse.gemini.blueprint.util.internal.PrivilegedUtils.executeWithCustomTCCL(PrivilegedUtils.java:85)
	at org.eclipse.gemini.blueprint.context.support.AbstractDelegatedExecutionApplicationContext.completeRefresh(AbstractDelegatedExecutionApplicationContext.java:290)
	at org.eclipse.gemini.blueprint.extender.internal.dependencies.startup.DependencyWaiterApplicationContextExecutor$CompleteRefreshTask.run(DependencyWaiterApplicationContextExecutor.java:137)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ClassNotFoundException: com.atlassian.hipchat.api.cards.Card$HtmlActivity not found by com.atlassian.plugins.base-hipchat-integration-plugin-api [223]
	at org.apache.felix.framework.BundleWiringImpl.findClassOrResourceByDelegation(BundleWiringImpl.java:1532)
	at org.apache.felix.framework.BundleWiringImpl.access$400(BundleWiringImpl.java:75)
	at org.apache.felix.framework.BundleWiringImpl$BundleClassLoader.loadClass(BundleWiringImpl.java:1955)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	at org.apache.felix.framework.BundleWiringImpl.getClassByDelegation(BundleWiringImpl.java:1374)
	at org.apache.felix.framework.BundleWiringImpl.searchImports(BundleWiringImpl.java:1553)
	at org.apache.felix.framework.BundleWiringImpl.findClassOrResourceByDelegation(BundleWiringImpl.java:1484)
	at org.apache.felix.framework.BundleWiringImpl.access$400(BundleWiringImpl.java:75)
	at org.apache.felix.framework.BundleWiringImpl$BundleClassLoader.loadClass(BundleWiringImpl.java:1955)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 21 more

Cause

Your Confluence HipChat plugin is too old.

Solution

Update the Confluence HipChat Plugin at least to version 7. It can be done via add-on management in your Confluence instance: