What should be done in the caucasus mountains and the eastern border of Iran? I trust you don't want a several-kilometer cliff face.
You're right, I don't. The Caucasus are unchanged, but as for "Iran"'s eastern coast, I imagine either gentle sea cliffs or sea-level beaches.
For bodies of water which were filled in, such as the Baltic or the Gulf of St. Lawrence, what should elevation be?
Preferably, a flat Baltic Plain and Saint Lawrence, as the instruction map, is a part of the Appalachian Red Line.
How tall is the Carpathian Plateau?
All I know is this--not as tall as Tibet!
Your verbal instructions indicate that all of mainland India should be lowered by one color, except the Himalayas, which will be raised by one. However, the line you drew appears to be quite a bit south of the Himalayas. Which should we trust?
Could you clarify on that? I don't understand the question.
Which color scheme are you using? How much is "one color"? (I would personally recommend X2; the 8K-BAM topographic map is already in this color scheme, so that would be easy).
Actually, it'd depend on which color scheme you would be using, if you're still interested. For example, this map has a seven-color scheme. This map, nine. This map, eleven. This one has gone as far as an eighteen-color scheme.
I assume that the instructions which stretch across the former Middle East refer to the Mediterranean Islands.
You assumed correct.
Edit: Is this an equirectangular projection?
Yes, it is.