So I put my TV capture card in my Core? or MD? or both?
All of the above works. MythTV has two components, a frontend and a backend. Each MD (including Hybrids) will launch a frontend when you press the TV button. Multiple backends can work together in Master/Slave configurations. Therefore in any machine that has a TV Capture Card it will run a backend (linuxMCE runs a backend on all MDs and core by default). The backends will work together so that they appear as one and all frontends can use any of the capture cards. My suggestion would be to put them all in the core as you are guarenteed that this will be running.
Do the IR devices to turn on my TV and Reciever connect to my MD? or Core? (This one seems simple but would like to make sure)
Usually the MD or a dedicated device like a GC100. You basically want it near them because IR must be line of sight.
Does the MD need a HDD at all if its PXE booting?
No, but you can has a HDD with another OS installed if you want and sort of sual boot them.
So if I want to add new devices to my MD(such as Bluetooth), I plug it into the MD I want, but configure it on the Core? Cause the MD is Volitile, right?
Sort of, you are plugging them into MDs and configuring them through the Pluto interface or the admin web application (which is hosted on the core).
btw: The whole file system for the diskless MD can be found on the CORE and this can be useful for checking logs etc without turning the MD on.
In the case of IR devices, if I am suppose to have IR devices connected to the MD(See above question #2) do I need multiple IR Recievers for each entertaiment device. For example, say I have a TV, VCR, and a Reciever. Each can be controlled by their remotes, which work via IR, so I need 1 IR Reciever for each device? Cause isn't IR "line of site" comm. Furthermore do the IR entertaiment devices (TV, VCR, Reciever) IR sensor need to be pointed directly at the IR device going to the MD?
I think you may have confused the terminology somewhat. You need an IR sender to control your IR devices. The devices themselves will have receivers built in (if they can be controlled by remote). You should only need one sender but it may have multiple IR LEDS which can be positioned to control multiple devices.
I can understand that these questions are elemantrary, but its more of a reasurance than anything else.
Thank you a bunch for your replies.
Hope that helps