In answer to your question, yes all that is possible plus more. Now, you must know that I'm a "neeeewbeee" on this site, but even being new and after reading all I have been able to you can do the requested plus more.
The advantage of going with LMCE is that you also have the ability for media (video/music), telephone (asterisk) and what ever your mind can come up with. Now being an asterisk and linux "expert" as you put it I don't think the full blown system would be a prob, but as posde was (I think) suggesting was that if you don't need media, asterisk and other things that there are more simpler ways of just controlling lights, curtains, thermostats, etc....
Most of the manufactures of lighting controls, thermostats, curtain climbers offer controllers that will control their devices. Do a google search for "home automation equipment" and you will see that.
Now to my main question for you. If in fact you are a asterisk expert, you also know that this is doable within asterisk. Controlling of the less advanced stuff like light switches, door bell monitoring and control, video surveillance can be done through asterisk and the sms module even using twitter as the access to the controllers. I've been doing it that way for a few years. I came to LMCE to go advanced by including media and having one type of controller I could depend on for all functions.
Now, I'm not for sure but from what I have seen on here I think the forum would welcome your expertise in the area of asterisk and would hope that maybe you will stick around and grow with the rest of us. I am a ACE, but even so, I can always use other peoples input for I'm not a master by any means.
That's my input. Stick around, who knows it might be interesting.