The Tapo C425 cameras are compatible with the Tapo H200. The Tapo T310 room thermometers are not listed in the available compatibility lists, so I cannot tell you for sure about the compatibility of these sensors. I recommend you to consult our Community or contact TP-Link support to get certainty.
No, there is no suspension prepared, but the HUB with a size of 7 x 7 cm is so small that you could easily stick it to the wall with strong double-sided adhesive tape.
H100 can do less and can only be integrated via WLAN. H200 has Lan connection, SD card slot, siren and external power supply unit. I only use the H100 as a siren.