1. While I have a feeling this isn't exactly what you're looking for, take a look at this link: http://www.ecadconsultant.com/tips.html#Wiring_Diagram. While you're there, you may want to poke around as it's an informative website.
2. *ACADE manages the data for your project, enabling you to extract, on the back end, a large array of reports. This requires that you, on the front end, input certain information when placing symbols. Mostly, this is description, catalog information, and sometimes one or two other details. *ACADE can do lots of project-wide functions: number all the wires in one fell swoop, retag all schematic components, update all title blocks. These functions also work by the individual drawing or work on a set of drawings defined by you. *ACADE will allow you to separate things by their location - for example, we separate our main control panels from our remote control panels with the Installation/Location function. When laying out the panel drawings, I can extract only the components that go in the panel I'm drawing. *If you place a relay or contactor, and if it's in the catalog properly, then ACADE will keep track of how many contacts you've used on that device. It will tell you if you try to add more than the catalog info says it can hold. *There are also a bunch of editing commands that make things easier. Whoops, did you accidentally make that contact N.O.? There's a command that will make it N.C. while maintaining all other aspects of the block, like all that data you entered on the front end. In normal ACAD, if the contact was a block, you'd have to delete and replace. *Which reminds me, in ACADE, you can swap a block for another one. Like, just replace them without the need to delete, purge, and re--insert. *If your panels have bulkhead connectors, ACADE's parametric connector tool comes in pretty handy for showing that. *There's also a parametric PLC builder that will basically create any PLC you can dream up. Although, there are a large number in the catalog already.
3. If you're doing business in North America, then you can probably expect this. ACADE seems to be the dominant software here. We've seen a couple of people we work with make the jump to One AutoCAD this year, attracted by the idea of buying one software and getting all the different verticals in one bundle. Some of them coordinate with several industries and engineering disciplines, and so it's a no-brainer for them; they get value in being able to jump from ACADE to ACADM.
4. This one's been answered pretty thoroughly, lol
If you're trying to be aware of ACADE's benefits, be aware of its shortfalls. Explore this forum, there's plenty to see both good and bad about what people think about the software. For me, the biggest issue is that the catalog information has never been universally updated since its inception. Autodesk has always left it up to the vendors to voluntarily submit new information. Not many have. However, ACADE provides you with all the tools you need to maintain the parts catalog, to add, delete, or edit the entries as product lines are born, evolve, and die. Another thing that many see as a shortfall is the need to use ACADE's menus and commands, rather than 'vanilla' ones. However, as Brad noted, using these commands triggers activity in the background. Changes are written to databases, and sometimes drawings are opened and updated right there in front of you. ACADE does try to force you into certain workflows, but that's really so that it can keep track of data management. Normally, it's deviation from those workflows, or using a vanilla command when ACADE has its own version of the same thing, that cause problems.
And, I highly recommend that your crew get some good training. The more firmly one is entrenched in making electrical drawings in vanilla, the more difficult it is to adopt the ACADE ways of doing things. But it's almost certainly worth the effort, if done right.
Good luck!

Jim Seefeldt
Electrical Engineering Technician