Our servers are running with 100% uptime recently so it's definitely not the server's fault. The most obvious reason why your Host cannot connect is a firewall problem, namely blocked outgoing ports which are used by the Host.
NOTE: the article mentions version 6.5 which has not been released yet. The beta is coming this week though. In this new version the number of ports will be reduced - in fact you'll only have to have one outbound port open (5655) in addition to port 443.
You mean the Host icon in the system tray, correct?
If so, I'm afraid this cannot be possible. The icon is part of the program branding, besides it must be immediately recognizable due to security reasons and be associated with the program that runs behind it. No doubt antivirus software companies will frown upon this ability, should we start to provide it.
Also, will the beta update be available via the in-app update check, or does it have to be downloaded manually?
Usually, we do not enable automatic notification about beta updates, only stable ones. But the beta version will be publicly available on the site so anyone can download and use it. We will be looking forward to receiving feedback from beta testers.
Your settings are correct. This is by program design - when you move your admin mouse pointer the remote mouse pointer also moves, but not vice versa. So inevitably if you once move your remote mouse pointer (by physically moving the mouse) and then the admin moves hers the remote pointer will "jump" to the admin pointer location.