Hello J
In answer to your questions:
Firstly for controlling your heating/cooling devices, yes the AM12U will do this provided they are within the switching loads of this module. Also consider the X10 Appliance module 2G see:
http://www.uk-automation.co.uk/x10-a...le-p-1181.html
Secondly you can control your AV equipment using the X10 Infra-Red transmitter. This has learning capability from your existing AV remote control and commands can be assigned to particular X10 codes allowing IR to be transmitted when the correct X10 is received, see:
http://www.uk-automation.co.uk/x10-i...er-p-1412.html
Thirdly, if you are restricted from replacing switches then your only option for room lights is the LM15EB or LM15ES (bayonet fiiting or ES screw fitting). For table lights you can use the LM12U or AM12U.