Pretty sure 3M wouldn't recommend milling the ultimate on anything other then their 3M Mill/Jensen VHF..which are both dry, so I think it's safe to say that it's made to be milled dry.
He's probably outputting using a different STL output then which is splitting the files up. Hard to say thought without looking at it. He should be able to get one solid stl no problem.
Not if he's still outputting a DCM. Something isn't set up right in your Manufacturing Processes section of the control panel and/or when the order was created he didn't select the material/process that outputs the STL. Double check your settings as you should have no problem getting an STL out...
Re-modelling an order shouldn't reset anything so I wouldn't be worried. if you don't feel comfortable re-designing then you can always right click the order and do a 3D Preview and then draw a cross section and measure on that plane [see image below].
I don't know of any 3Shapes being sold nowadays that are truly closed. They may have locked in certain materials but it's as easy as making another material and setting the output to STL in the control panel. Nobody is closing the model builder portion of the software though, so you can get STL...
I can't say for sure, sorry, but you will most likely need a special fixture to hold the bridge up so that it can scan the top and bottom of the bridge. That, or possibly adding scans later to fill in the voids. For 3Shape you need a special wax-up bridge holder that holds the bridge so both...
3Shape doesn't support scanning a post and core waxup (that I know of),the only way to do them in the software is to use impression scanning and do it the right way. You could however try scanning it in, upside down, as a pontic or other form of anatomy in the ScanItLibrary to get an STL but...
Chances are he doesn't have model builder though and even if he did there are 3-4 different versions so he probably wouldn't have the right one. What kind of scan did the doctor send? What file type? Full arch? Is it virtually ditched?
Best thing to do is to limit the amount of cases that even show up in the Dental Manager. Go into your control panel, under General Settings there is a checkbox to limit the amount of cases and then you can punch in a number, I'd say >200. The Dental Manager should load up faster. That may be...