Nick,
nice set of questions! I think I can help you because I have been researching this subject for the last months!
First of all I have to say that I saw some installations using computers and software automation that can pretty do as much a full blown Crestron system can do. I don't really know if they can have the 99.9% reliability of a Crestron and Lutron setup, but at a fraction of that price you can't really complain if they don't. My favourite one is from this guy who uses homeseer. Check his site here:
http://www.pksweb.com/ha.htm
Homeseer can control all of the equipment that you are interested in controlling. And it can use a touchscreen interface. Is is compatible with mainlobby from cinemar. Most people use the viewsonic tablets to control their systems. You can buy them in ebay.
Personally instead of using the computer for RS232 and infrared I decided to buy the Global Cache GC-100 which has two RS232 ports, 3 relays and 6 infrared outputs or inputs. Also the model I have (GC-100-18) has 5 additional expansion modules so you can add more infrared, relays and RS232 ports if needed. The GC-100 connect to your network by ethernet and is fully controllable by Homeseer and also another home automation software I found ok called housebot. The other software worth mentioning is CQC (
www.charmedquark.com) and there is a guy in the avsforum with username IVB doing some nice things with it using RS232 from his PC. Go to
www.avsforum.com and serach for posts by IVB. Although now I use homebot I think i will end up with Homeseer because it is more powerful and it can do everything I want. The forums of the three softwares mentioned above are very good sources of information.
I think the main reason for choosing RS232 for controlling your equipment over infrared is that RS232 is bi-directional hence you can get feeback from your equipment. This is really useful if your equipmnt is in a closet and you would like to know for example the input and the surround mode of your av amplifier.
I am nor a really fun of X-10 because I found out many people were experiencing a lot of problems using it. It uses the home's power lines so it is subject to interference. You can control the equipment (diy 12v plasma screen lift, diy 12v electric reclining seating, curtains, projector screen) that you said that you want X-10 using relays.
For lights pesonally I am thinking for Rako. They do not require rewiring, they save you electricity when you dim and they have an RS232 interface. I have also bought some z-wave lamp dimmers from lets automate and they work very well. Homeseer and housebot are compatible with z-wave. The think is I just got an e-mail back from Act Solutions and it seems that the European light switches and dimmers would not be out for at least 6 months. Check out x-10 too. If you don't get interference and they work ok in your setup, why not?
I prefer touchscreens to present control options only and not mirror the mce. Homeseer has a mce plug-in but I do not really see a reason to use it if you have a touchscreen with mainlobby.
Other companies that make software that can enable mce to be used for home automation are:
http://www.embeddedautomation.com/ ,
http://www.exceptionalinnovation.com/ ,
www.onev.com ,
www.securegen.com
I use the Sonos systems for Multi room audio. There is a script in the homeseer forum so you can control it through homeseer if you want, but that is no really needed as the sonos controller is excellent.
I think you should divide what you would to like to do in sections, for example: lighting, audio distrubution, video distribution, climate control, infrared and RS232 control for av. Then you should choose the equipment you would like to use for each section and find a software that can integrate and control the equipment. It is not as difficult as it sounds. Read the above, do some research and come back to discuss some more. I hope I haven't confuse you!
Linear Mode
