Oh dear oh dear oh dear !!!!!! Cables under carpets......!
The short answer (i think) is yes to all the above !
Re the Radio costs, it's true what you say Wiz, radio can be more expensive to maintain, I never hide the fact I consider them to be a "high maintenance" system.
However, I would have to add that we do monitor all our systems and log faults etc and that we have several radio systems installed for over four years now that we haven't had a "proverbial peep" out of.
We have others over 10 years that can be a pain.
We tend to have troubles with the older systems using lithium cells.
The newer stuff runing on Duracells appears much more reliable and drastically reduces the battery change cost. - And you always have the option to lease !
