I will parlay on your advice about codes and hopefully say something meaningful here. I live in New York, The land of code nightmares where State building inspectors, fire inspectors, local town and city buildings inspectors will be looking at your work with extra pencils and clipboards and have no problems breaking your balls for stupid stuff that they just wrote a new rule for last week. I know a installer who installed a cctv system 6 years ago and had the building manager call him back because Mr Fire inspector told them that he tied off some cables to a charged water pipe for the fire system, turned out that pipe was a major run for him, he was pissed but he did not know the code and it cost him a day of re running cables. If you run non plenum cable above the drop ceiling and there is a fire with a lot of smoke damage, the Insurance company might be coming for the guy who installed the wrong cable that contributed to the smoke damage. I you install a dome or bullet in a ceiling tile and did not secure it with a cable or mechanics wire to the rafters you will be called out on that, reason being if the tile gets wet and it drops on somebody's head its on you. I see a lot of bad stuff every time I pop a ceiling tile. I know that mess of communication and old dead cat 5 cable could be a lawyers goldmine if they could prove job incompetence on your part. You can do whatever you want in your own house and chances are it will work but if you burn it down from doing something "OUT OF CODE" and the fire inspectors write that for your insurance company, they might not cover it, I know its a slim chance but it something to think about.