Jason,
Thanks!
(1) Yes, switch to 'canvas' mode to turn off the map background. We added that last month: New Blank Canvas Camera Calculator Released
(2) "get a just full size image of the camera layout" I would recommend using export / snapshot to do that. That way you can get an image of exactly what area you want.
(3) "decrease in PPF over distance with color gradations?" We have had a number of requests. It's being considered but not right away. See below.
(4) "what is being worked on for the next update?" The next big thing is the mobile app.
"Does IPVM need to raise the subscription fee a little bit to help facilitate improvements on a faster basis?" While I greatly appreciate the thought :), we are not planning to raise any rates as it would be disruptive.
In terms of what we are working on right now, the last 2 months have mostly been in redesigning the entire website. We've ripped most everything apart and that's made it hard to do much of anything else. When it's done in ~10 days, (1) the site will work nicely on mobile (today it sucks), (2) be significantly faster and (3) easier for us to maintain / extend the codebase.
Once we get past that, we can focus more on adding features to the site and the calculator.
I do want to emphasize the calculator is our top development priority as it has already been a great success and a money maker for us. People sign up just the calculator all the time, so we are quite motivated to make it as good as possible.
Finally, we will look to dedicate a post just on calculator development. For right now, others can jump in with ideas here. Thanks for the great feedback!