I had to leave my office so they could use it for an interview so I'll finish in a new post from the other room.
To me "I meant to do it" indicates I intended to but didn't regardless of how important the task was although it often preceeds a weak excuse. "She is/was meant to" indicates some kind of cosmic choice, like "it was meant to be". "Meant for" which looks awful in print is used around here to mean "intended" whether or not the intention was fulfilled. "I meant for that to happen."