Not sure why this has gone cold as it’s a brilliant price - heat OP
Add https://www.amazon.co.uk/dp/B009SA9Z6S?ref_=plp_pc_dp_A5QFPKEDONCGF_B009SA9Z6S&me=A3P5ROKL5A1OLE to your basket and you get 15% off both items meaning you get the camera set and the Belkin Wemo plug for £531.
Yes. You can also leave them on powered if you prefer.
Yes, but that is the problem if you want wire-free CCTV. Just mount them properly and securely in a hard to reach location.
Also if your cameras are quite high, I assume you need a ladder every now and then to charge batteries