I suspect you don't understand what you see in Activity Monitor. My Mac has been on for a few weeks, and I run Safari all the time with lots of tabs. Currently I have four tabs open and Safari is using 292MB of RAM. I just launched Notes and it's using 35MB.
And neither comment #2 or #3 are relevant to the story. Logic Pro X is about making music, which includes editing. Resolution and fidelity is important during the creative process, but less so during delivery and consumption. Logic is not iTunes.