Images Attached below:

Ok, first let me say thanks again for all the advice. After thinking long and hard yesterday about how I wanted to proceed and after some limited research I came to the following conclusions (putting aside my serious river problems for the moment). I apologize in advance for my limited real cartographic knowledge and for any gross oversimplifications that may follow, and please correct me if I'm wrong.

-The area of the map using a Mercator projection with the "least" amount of distortion appears to be between 60 degrees N/S of the equator.

-On the Earth our primary population centers also appear between 60 degrees N/S of the equator. Furthermore, 60 degrees N/S of the equator on Earth appears to be the primary zone of habitability.

-On Earth the tropics are approximately 23.5 degrees N/S of the equator.

Taking these assumptions into account I have applied the following reasoning to my map.

-If my map's focus was narrowed to between approximately 62 degrees N/S of the equator I would have to worry less about extreme distortion.

-If I considered that my "planet" was of a generally colder climate than earth and that the "tropics" were limited to about 13 degrees N/S of the equator, less of the extreme north and south of my planet would be habitable; therefore justifying a map whose scope was more narrow. (As a side note a colder climate on the planet may be due to an ice age or mini ice age, which could also explain the lower sea levels and the increased percentage of land mass to water on Aetherworld, approx. 50/50, as compared to Earth.)

-If I have less to worry about as far as Mercator projection distortion due to the more narrowed focus of my map I could declare it a Mercator projection without stretching reality too far.

With those assumptions, and after the baby and the wife finally went to sleep, I was able to make some modifications to my map. I came up with two basic alternatives, both using Hai-Etlik's graciously provided svg files of Mercator long. and lat. lines and Rhumb Lines. Please review these and see if they make sense following the above logic. Let me know what you think. Also, if my logic makes sense let me know your preference visually between the Rhumb line and Lat./Long. versions of the map.

Oh, and per Ramah's suggestion I decreased the opacity of the country and continent borders. Finally, I have relocated my island continent further north to more align its climate with what I was imagining.

Attachments:
Photoshop World Map (Mercator Rhumb Lines) Thumbnail.jpg
Aetherworld, Mercator Projection, Rhumb Lines

Photoshop World Map (Mercator, Long and Lat) Thumbnail.jpg
Aetherworld, Mercator Projection, Lat. & Long. Graticules