There are significant bugs in the copy/paste:  

#1, as I said before, whenever you paste to a table, all your formatting of that table, resizing in particular, is reverted to default, which messes up relationship lines and makes spaghetti out of it. Some of those here may not care so much about pretty models, but I do and so should Vertabelo, since pretty models help sell product. And they make it a lot clearer and easier for the business client to understand.

#2, and probably more important, when you copy columns, that copy gets stuck in cache and not cleared. I've copied and pasted columns, then tried to copy a description, and all I get back are the columns, over and over, no matter what I do. I paste the definition I tried to copy or cut, hit control-V to paste, and the table where I pasted the columns gets another set, and another, and another... into infinity. I have to close the browser and open up the model again to clear cache. Please fix this!

I have found and used the column copy. I created a table with all my audit columns, I select the columns I want, hit control-C, position the cursor over the target table, and hit control-V. It works, yes.  HOWEVER... I have a carefully constructed relational model, with the tables sized to handle many relationships to core tables. As soon as I paste even ONE column to that table, the table resizes down to the minimum, throwing all my relationship lines into a tangled mess.  And, in Vertabelo, once a relationship line has been broken, you have to move that break and manage it and the lines no longer adjust in a reasonable manner.  I've figured out workarounds, but I would prefer you NOT resize the target table, just because a column or two was added.  expand it to accomodate the additional column(s), fine, but don't minimize it; that's really a pain in the neck.

Okay. Thanks. It's messy, but it works. The boxes are resized when I paste, which throws all of my carefully-drawn relationships out of whack. Can't you do a check, first, to see if there's enough space in the table graphic to house the new columns and, if so, don't resize the table/box?  I take significant time to draw my models and size the boxes so that relationship lines minimally cross, and this screws all of that up every time I paste columns.

For the record, these are the sorts of additional features that make a nice quick-and-easy modeling tool into an enterprise class tool. (That and a repository with version control, but that's a huge ask). 

Alternatively, for Audit columns, ER-Studio has a macro feature that allows one to define a standard set of audit columns and add them to all tables as part of DDL generation, so that the Logical Data Model is not "polluted" with a stack of physical-only attributes that make for a far less-business-friendly model display.

This is copying/pasting columns, not tables. This is available in the top 3 data modeling products -- visual column select (one or many), copy, and paste.  In PowerDesigner, they allow CUT and paste, only, so you copy/paste a table, move the columns with click&drag to the target table.

What you say is true, but it's the constraints that are not sequenced correctly. The child constraints must be dropped before the parent constraints, or it will fail.  We will update with an example, but that's our issue. As created by the tool, the DROP sql will fail.  

Also, why do you NOT have IF EXISTS statements for the DROPs?  That is an easy addition, then you could include the DROPs up front in the DDL and we wouldn't have to mess with failed DROPs and multiple SQL files.  All the major data modeling tools I've used have allowed us to generate a DROP/CREATE sql with an uncheck option if we're doing it for the first time in that environment. But the IF EXISTS would allow us not to worry about the DROPs unless they're needed.

First things, first, please consider a reasonably complex model and how you generate your constraint statements, in what order? We will get you an example as soon as possible, but the constraint sequence is the problem.