1: If I get a 32 bit OS running 4 gigs of ram on a mobo that has integrated graphics, with the remainder of the ram that isn't recognized by the OS be ported over to be used by the integrated graphics?
2: With the same situation, if I wanted to get a 256 mb dedicated graphics card to use in conjunction with the integrated graphics, do I need to do anything special, or will the system take care of everything for me automatically?
You have to set the amount of memory that the IGP can use in BIOS, it wont just use anything not used by other things in the system. Also if you are doing a new build the only reason to get 32 bit is if you have an old device that you absolutely cannot live without that does not have a 64 bit driver.
Any dedicated card you get will be more powerful than the integrated graphics so you just need to connect the cable to the graphics card and it will use that instead.