Ad. 5
You can draw lines on your map - to help with your mission planning I presume. The "Draw"-tool is on the left in the middle. Not really sure what the Eraser does (erases them) - I usually tab "Clear guides (or lines?) when I want to clear the lines I've drawn.
Ad. 8
It seems to use the video cache for the Director - if you want to edit quick videos on your device. Also, it might be handy in case of an accident where you lose your Phantom. If using an iPhone or iPad you can access the files in iTunes, click APPS and click the DJI Pilot App, you can then see the "documents" - and then you can Save As the files to your computer. These are 720p video files captured from Lightbridge connection I believe. If you have room on your device I don't see why you should not have it enabled - just in case, or for when you want to use Director. So ultimately your digression.
Ad. 9
I would have it turned on - I assume it uses the GPU-features on your device to display the live video in the most efficient manner. Try turning it off to see what happens? I could imagine that if you had problems with the live-feed or the app crashing, this might be something that might be worth trying to turn off. Also, older devices might not have the feature so they can't use it. I'm guessing a bit here - but it is likely not of any concern.
Ad. 11
I would not fly so far away that it was an issue. But I would think that Custom would allow for lower quality - thereby less bandwidth, meaning it should stay stable (but not as pretty) for longer. Setting lower quality might also be an idea if flying in a heavily wifi-congested area. So the option is nice - I just haven't tested it out - or had the need to.
Ad 13.
Colorful photos at night? thats a tough one!  There needs to be some light, obviously... And colorful and night does not sound likely. However, you CAN switch to Manual mode and manually set the exposure-time really high. You can go as far as 8 seconds - but that will likely create blurry shots, unless the Phantom is super-stable (it might also help getting a good distance away from what you are filming - so the tiny inevitable movements won't be noticed as much).
Ad. 14.
Same as 13, but there is another trick that can help (but remember it is not a night vision camera...!). You can use "bracketing" - hold down the shutter button and a menu opens. Select 3 or 5 brackets. 5 brackets for the highest amount of HDR (High Dynamic range). It will then shoot the image at low exposure (dark) and normal and high exposure (light). You can then combine those photos in for example Adobe Lightroom, into a HDR-picture where it uses the detail from both the dark and the light areas of the photo and combines them into one higher quality photo. This might not work too well at pitch dark - but shooting sunsets or after sunset or against the sun or in dark situations, this is really a great feature. Takes some work - but you'll appreciate that great shot. Photography, in my opinion, with the Phantom 3 is more about getting a few great shots you will cherish, than shooting a lot like we might be used to do with a mobile phone these days.
Also, I suggest shooting in RAW (I shoot in RAW+JPG). Takes a little longer for the shots - but you have more freedom editing afterwards.
Also, I shoot in LOG-color-mode and even turn down the contrast even further in Custom Style. That creates a bit boring looking "flat" photos and videos - but gives me the maximum ability to color-grade and add the darkening or lightening of parts of the video/photo and get the look I want. This is more difficult to do if you are already shooting "Vivid" or similarly photos with high contrast - where some of the image-data has been lost.
Thats a few answers and suggestions. Hope some of it will be useful 
- Buy your DJI-gear, batteries, cases by using this link - it'll help me out 
| 
lvl.2
Second Officer
lvl.4
There needs to be some light, obviously... And colorful and night does not sound likely. However, you CAN switch to Manual mode and manually set the exposure-time really high. You can go as far as 8 seconds - but that will likely create blurry shots, unless the Phantom is super-stable (it might also help getting a good distance away from what you are filming - so the tiny inevitable movements won't be noticed as much).
