I'm glad you like iCam
No video or audio data is ever sent to the server. Nobody can intercept the data by listening on UDP ports 12000-12100 (or any other ports). The main security worry with iCam is the login and password. If somebody knows (or guesses) your login and password, they will be able to view your webcam. Of course, this is true about your email and your online banking as well. Make sure that you pick a login/password that can't be easily guessed by other people.
iCamSource doesn't keep a TCP connection with the server, but it does send periodic packets to the server to let the server know it's still there. If iCamSource is left running for 24/7 for an entire month, these packets will use about 60 MB of bandwidth during the entire month.
The video data is sequential JPEG frames (similar to MJPEG) but it doesn't actually include the MJPEG header data.
It is possible for us to add tweaks to brightness, contrast, etc, but it wouldn't really be night vision, which requires an infrared camera with infrared LEDs. There are actually a lot of cameras available with infrared capability.
A log of notifications is possible, I'll add it to our list of potential features to add to iCam in the future.
Recording has been requested by other users, and it is definitely on that list of potential features to add to iCam in the future.
PTZ controls have been requested in the past. As you guessed, the main issue with implementing them is that the control interface for each brand of camera is totally different.
I think I hit all the questions/suggestions there