KanColleTool is two things.
A tool to view information the game doesn't show you, and information it does show you in a more convenient way.
It's a small window that stays quietly in the tray when not in use, that will also notify you of completed constructions and repairs.
A viewer for the game, a convenient launcher optimized specifically for KanColle.
If you're using Flash Player Standalone/Flash Projector for the game, think that, but better.
As an extra bonus, it'll translate the game into English for you, and let the Tool livestream data.
If you're a foreign player, DMM already have all the reason they need to ban you.
Using KCT will not increase your chances of getting banned, and starting with 0.7.1, not even I could tell if you're using it.
The tool and viewer will both identify as Google Chrome (in 0.7.1+), so all they have to go on is the location your IP originates from.
Aside from the normal reasons (new features and bug fixes), new updates are sometimes necessary to stay under DMM's radar.
TL;DR: Always update. It could be important!
You most likely do not have Flash Player installed.
This is especially common if you use Google Chrome as your main browser, as that uses its own, embedded version of it. It's not possible to load their embedded version into another program, so you have to download and install Flash Player yourself before KCT will work.
As an extra bonus, this will fix videos in Steam not loading.
On Windows, we have to bundle our own WebKit with the application. This is the web rendering engine used by Google Chrome among others, and a really good one at that, but with the drawback that it's pretty freaking big.
On a Mac, we can use the system-provided WebKit version, and on Linux we simply depend on it and have the package manager provide us with one, but on Windows, neither of those exist, and thus we have to bundle it with the program.
There are two main things that could be causing this:
The patch works by laying a filter between the game and the server.
When the game requests some data from the server, this little filter (a protocol/reply handler, depending on the system), catches the response and looks up translations in a database, swaps the Japanese text out for English, and hands it back.
The beauty of this is that the game can't tell any of this is taking place. It just displays whatever it thinks it got from the server.
Sure, just head over to the Documentation page. That has everything I know about how the game works.
Using the save on disk feature, screenshots will be saved on your Desktop. Using the upload function instead, an Imgur link will be pasted to your clipboard once the upload is complete.