Open two maps at the same time?

Is there a way to open two maps at the same time so you can copy/paste stuff faster?

Not to my knowledge. Possibly if you have another WE program.

Sure, if you open one map and then open another, they'll both be open. I believe you can swap between them from the Window menu. However, when you swap it'll have to de-load the data of one map and re-load it on the other, which takes time.

What kind of data are you trying to transfer? Are you interested in overwriting the data of the map you're copying to? If so, there are other things you can do to copy data over.