Not at this time. The CrashPlan application must reside at /Applications/CrashPlan.app.
No. Only one instance of CrashPlan can be installed on a single computer.
If you have multiple users on one system and you'd like files from all users backed up, then you must install CrashPlan as the root user (Mac, Linux, Solaris) or SYSTEM user (Windows). To restrict access to Restore and to the CrashPlan desktop, require the account password to access the CrashPlan desktop via the client's settings and only grant access to an administrator.
Yes; the two pieces of software do not conflict with each other.
This error is given if the client cannot connect to the PRO Server. You can test this computer's ability to connect using telnet. If telnet connects successfully you'll see an encrypted connection string. If it cannot connect, then CrashPlan will not be able to either.
telnet host port
#Example: telnet central.crashplan.com 443
If telnet connects but CrashPlan cannot, review the following items:
No. The current version relies on interaction with some native libraries/code which is not currently supported on the FreeBSD platform. At this time, there are no plans to add FreeBSD as a supported platform or support CrashPlan on FreeBSD in any way. If you'd like to see us add FreeBSD support in the future, please add your comments to this topic in our Feature Requests forum.