Sky-Watcher What's Up? Webcast: CQ350 Pro Product Overview 

Yes, it can be pier mounted and works great for visual. It uses the same foot print as the EQ8-R so any pier adapter for an EQ8 will work on the CQ350.

We had the Esprit 150 and 120 on two CQ350s at the Texas Star Party and they worked lovely.

Hi SkyStory. We're not aware of any issues with the USB hub. The mount ships with a powered USB cable to take care of any distance issues (unless you're cabling this thing from your back yard , through the house, up the stairs, etc). A quick Google search hasn't brought any other potential issues to light. If you have a specific issue to ask about, email support@skywatcherusa.com. Alex will be happy to help you with any hiccups you may be experiencing.

Yes, there is a spacer issue. Check in with tech support for the quick fix.

They are spring loaded so the spring will give way allowing the gear to slip if this ever were to happen.

The payload capacity on the CQ350 is 77 lbs. Assuming you're asking about the LX200, then no, as that OTA weighs 110 lbs.

@Sky-Watcher USA its an lx850