<<I thought if you pushed it all the way in you couldn't use it as a direct out?>>
no, you CAN use it as a direct out if you push the cable all the way into the insert. however, that interrupts the signal flow through the board, so if you want to take advantage of the Aux sends for headphone mixes, etc., you're screwed.
when you "tap" an insert (only pushing it into the first click), you're effectively tapping into the signal and you're not interfering with the way it travels through the rest of the board. that's the benefit. you get a "direct out" AND you can still use the board for other routing functions. tapping the insert is the "poor man's direct out".
as far as what an insert does....well, say you've got a compressor that you want on your vocal channel. you use an insert cable, plug it into the respective plugs, and you can send the signal from the board's preamp out to the compressor and then back from the compressor to the board--you can then eq and raise the level of the channel in the mix, etc., as you see fit. hence the reason it's called an "insert"--the compressor is inserted somewhere into the channel.
and yeah......my weakest link by FAR is the room. it's an unfinished basement and some parts of it actually sound real nice for recording
acoustic guitar and amps and vocals. but it's horrible for drums--the riser i made helps some, but still.......i need to get some drywall up (and most importantly to my wife above, a ceiling on the room) and start treating the space. all other changes i make are pretty much worthless until i fix my room.
cheers,
wade