As far as mounting options, obviously that’s mostly a matter of preference and what you want to capture. Keep in mind that the cameras detect motion a bit better when it moves left to right, so one of the angles might be better for that. However with the non PIR cams (v3 isn’t PIR) it doesn’t seem to matter that much, I have plenty that capture motion straight on no problem.
Rather than putting an outdoor outlet, you might want to consider mounting it near one corner of the garage door and just running the flat cable through there, that’s how I have one of mine. As long as the door doesn’t close super tight (and probably has weather strip to cushion it anyway) it should be fine that way. Also the option of drilling a small hole, just enough to fit the micro USB connector, and plugging it inside, then you don’t have to worry about a big weather proof setup in such a visible location.
The only spot I wouldn’t recommend mounting it is to the left or right of the flood light as there would be glare probably, but I believe you’re using those boxes to denote where the outlet would be?
If you do go with the outdoor outlet, you could mount it right above the floodlight with a short piece of conduit directly to the floodlight box, I’m assuming it has a knockout on top. Would help hide it a bit.
Obviously your floodlight would need constant power, which based on the fact that it is a motion sensor and I’m guessing has a dusk to dawn sensor in it, it probably does. But if it is on a switch, might want to put a cover or label on the switch so nobody turns it off accidentally. Along those same lines, not sure how familiar you are with electrical, but depending how it is wired there may be hot wires in there with a “switch loop” to the switch, or it may be direct fed from the switch. The latter is easy, you just have the normal 2 wires. The former you need to determine the always on pair and use that. But that also eliminates the switch issue if that’s the case, since you have a constant power source.
I have one mounted on the right side of the garage door, since my truck is on the left, and my back yard is on the right. It is a Panv3 so if you walk up my driveway it follows you into the backyard and can see where you go from there, and will also follow you around my truck (or even into the garage to a certain extent if the door is open.