Thanks, the advice was good and correct (sourced from member(s) here). I should have gone to a commercial CCTV company and set up some very quick CCTV capabilities. Such as a webcam + PC, looking out of window(s).
But in practice, I do really like the idea, of sorting my own CCTV system, and hope the following details, explain how it should give me very basic CCTV capabilities, reasonably soon, details below:
Update:
I've not had any further troubles, so far.
So, (Optimistically), I'm hoping that that is it, at least for many years, and longer to come.
But need to (Pessimistically, assume/design for the worse), devise and keep on top of my security solutions/implementations.
I've NOT dabbled with the suggested quick, CCTV fixes, such as mounting the wildlife camera. I want something more 'solid' and longer term. So, I'm NOT pressured, into very rapidly getting an expensive/complicated CCTV system up and running, too quickly.
Instead, I'm moving into implementing an initial/quick CCTV system, in stages.
From this thread, and other sources, also related to this forum (thanks!), plus more research by me. The recommendation seems to be to not get involved with the bottom end (non-professional) CCTV cameras, such as many of the Amazon ones.
It is not just their possible subscriptions, WiFi ones (as already mentioned), it is not the best of ways, to setup a reliable CCTV.
They tend to be poorer quality, in various respects.
So, (better details to follow, in later write ups), I've bought a set of high end, professional CCTV cameras, made by Panasonic, on ebay, at very reasonable cost (tested working, reliable ebay seller, one is even unused, so classed as new) (unfortunately they are these not so small, dome type, but I like their quality/PTZ, and great prices, I managed to get). They are very high end (a tiny/little bit old, but still fairly/rather modern ones, but they seem to suit my needs, very well), with PTZ, with zoom that is a real optical zoom type, 1080P, 40 metre IR illumination if required, full colour, even at night, even if there is only a bit of light. (as mentioned IR Leds if not, 0 lux).
Being professional cameras, they (if I believe their brochures), will give nice clean, smooth, auto-focused, and very well light balanced images, even under challenging lighting conditions.
They are PoE (just needs a single cable), mostly indoor only, but one outdoor rated one.
Apparently full featured network (IP) capabilities. I.e. A webbrowser pointed at them, will give lots of functionality.
To hit the ground running quickly, if I understand things correctly. I can give one (or more), a suitable SD card and PoE injected power supply, for now. Point it/them, out of a suitable position(s), such as a window, with the appropriate view(s).
Leaving them on continuous recording to the SD card (probably extreme high endurance type).
That will do for now and give me time (weeks or months), to setup something more permanent. If there are any further incidents, I know that those SD card(s), would hopefully have footage on them, of the culprit(s).
A more permanent solution, later, maybe much later, is to put one camera at the front, and one at the back. I've found suitable potential mounting positions. Would then put 4 way/channel (maybe more) PoE network boxes, front and back (single box would be too much cabling I think). Connecting each box to my (or a) network, so I can see multiple camera views at the same time.
I can then add more cameras (via those PoE boxes), at a later stage.
I still 100% agree with anyone who suggested getting a commercial company, to sort me out. But I'm still hoping I can lash up something, quickly enough, to meet my needs.
If the installation, beyond putting them in room(s), to see out through window(s), ends up being too hard. I will still need to consider commercial companies, to do the bigger installation work.
N.B. I haven't spent that much on the cameras (very approximately, around £15 unit, including postage, price varies, as two different varieties, involved), so still have plenty of theoretical budget, to get more suitable (extra) cameras and/or a commercial company in to do it properly, as future options.
The big advantage (to me), is that if I do it all myself. I will be able to readily maintain and fix it. As they will be as high as I can reach, with my ladder(s), and I will know everything I've done, to get them working.
It will take a bit of time, to get initially working, even for the quick test and setup, as I will need to sort out PoE injectors (they may have additional powering up means, I'm not sure at this stage, perhaps 12V inputs), the network connect(s) etc.
But I'd prefer a semi-decent, semi-permanent, but working solution. Rather than very quick fixes, but ones that don't really work out, too well.
Because, as I mentioned earlier. Even just one proper CCTV camera, set on permanent (loop) recording, if pointed to a front view. Should pick up >=90% of all incidents/activities.