What follows is just my opinion. I am not asking you to agree, or disagree.
Might I suggest that for mounting cameras you lift floorboards and drill through from outside to inside. (You want to do a job you can be proud of?) Fix a plastic adaptable box, mount the camera to the box lid. The one pictured below is mounted to a hollow pole, the cable is inside the pole, and back entry to the box, no visible cables to be seen.
If you want to see faces, you should not mount the cameras high up, 9-12 feet is good, if you mount them any higher, you will just get the top of their heads. If you watch any TV programmes that have CCTV footage, yes the cameras are often 25-30 feet up, BUT they have zoom lenses and have zoomed in from far away, which works, but for your average house you can't do that (Not to mention a camera with decent zoom is not cheap, and you have to be watching it all the time)
I have had people knocking at my door asking did my CCTV see (what ever) turns out they live almost the other end of the road from me, CCTV is not like you see in the movies, it doesn't see round corners.
Put it this way, when you are out, do you look for CCTV cameras? no, of course not, and neither do most folk after the novelty has worn off.
Don't bother with shotgun cable, it's like fitting halogen downlights, they were good in their day, but not any more. Cat 5 and POE is the way to go. Lots of videos on YT showing how to install a push through Rj45 connector.
Got to agree with binky, push through RJ45's are a doddle. (You strip the cable, lay the cores flat, push them into the plug, surplus comes out the top, and you trim it off) and if you mount the cameras on boxes, no need for waterproof connectors.
Cheap crimp tool and cable tester
Click here
I would not bother with dummy cameras, they look like..............dummy cameras, also unless you spend a fortune, genuine powered up CCTV cameras have a red glow at night. (They have infra-red LED's so you can still see in the dark)
I also have to agree with David R Connell, you do get what you pay for. Many many years ago I did use Swann, (Not much else about at the time, and no POE) but I soon realised yes it works, but it's not the best quality, there are loads more brands now.
I find that masking sensitive areas usually means you can still see it, but the NVR doesn't respond to it.
Just saying, personally I find the large black oblong as shown below really annoying (It's 3 cameras on an even number input NVR) but, each to their own.
Something not (yet) mentioned, monitor. You have CCTV but how are you going to see what is happening, who is coming to your front door? Yes you can use "Aux" on your TV but that means you have to find the remote, switch over, miss "the good bit" on TV, may I suggest you have a 2nd TV somewhere solely for the CCTV, yes it can be a bit of a faf getting a cable to it, but once done, you will not regret it. I use a small TV that I got while food shopping, most TV's now have various inputs and wall mounting brackets.