last weekend i used uglybob's diagnostic tool to see what codes i had in my ecu and it came up with the one for the map sensor being out of calibration range...... now, obviously theres a problem with it, but could replacing it with a new one help with the air/fuel ratio (which isn't to great) and the idle being a little rough?
all hoses have been checked so i know there isn't any leaks anywhere.....

9/10 times you have a problem with map sensors its the hose or connections but if they are all ok buy/borrow a another sensor

And yes, MAP issues cause AFR and idle problems.