Well I am a professional videographer and photographer and I will admit, I disagree with most of the information that has been provided so far in this thread but to each their own. You absolutely can use the P3 and make great videos; it is not the equipment it is the operator that will determine how the footage turns out.
1) I never offer 4K to my customers, DJI's horrible H.264 compression algorithm pretty much ensures that 4K will not look much better than 1080P so you don't need the Pro version to get equivalent footage.
2) I would never just "keep the camera rolling", that is a huge waste of space and a nightmare to edit
3) I do not use ND filters, the whole shutter speed problem is mainly a problem at night, in the daylight for an 8s aerial clip when you are 150-200ft off the ground with a 100 degree FOV, no one is going to notice the difference between 1/60s or 1/2000s for your shutter speed. ND filters add weight, they shorten the life of your gimbal motors (due to an unbalanced load), and as I mentioned, no one will notice anyway
4) I never hand over control of my Phantom to an app. Sorry, DJI has enough problems with their native software and firmware, adding an app on top of that is just a recipe for disaster. To comply with Part 107 you have to keep a LOS on the drone anyway, so the only thing you can do with one of those apps is get in trouble.
5) I shoot in either 30 or 60FPS (depending on if I want slow motion video), I never use 24P. Cinematic is great for Hollywood but when you are filming a real estate video customers want smooth footage. If you want to move up the ladder to commercials, car scenes, etc. you will be using something like the I1 or
I2 anyway.
Now--for what I do in fact do
I have the P3Pro, the P4Pro, the Inspire 1 pro, and about to get the
Inspire 2 Pro. Each one has their strengths and weaknesses. For real estate and construction videos I still use the P3Pro; why risk a more expensive drone for such a low paying gig?
Aerial videos are just overdone, it's like a new playground for people that have never done professional photography or videography. I only use Aerial video to establish the scene, without traditional video, an aerial video gets boring very quickly, unless you are doing something dangerous like flying low or close to obstructions. So if you want to make good aerial videos you first have to be good at making traditional videos. So I can easily shoot a 3 minute promo video and only have 30 seconds of aerial video in it.
Pictures - Always shoot RAW, edit in Lightroom, touchup in Photoshop as needed
Video - Corel VideoStudio is actually great editing software but a bit buggy when dealing with DJI's aforementioned H.264 implementation. I would start there and if you decide video editing really is for you, then check out DaVinci Resolve for color grading and Adobe Premier Pro for NLE editing. If you are on a Mac then of course FinalCut Pro is the only thing I would consider. Also, the Adobe Suite is expensive, but if you have an old college email address or a kid in college or anyway to sign up as a student (need a .edu email address) then you can get some pretty good discounts.
Anyway, I have rambled on long enough; I shoot everything from model fashion shoots with my DSLRs to aerial event videography; so yea, I've been doing this for awhile.