EO/IC...when the exhaust valve just starts to open, you adjust the intake valve lash on that cylinder. When the intake valve has fully opened and is almost closed, you adjust the exhaust lash on that cylinder and you check your settings using the go/no-go method. If your setting .020 lash then .019 goes and .021 no goes.
As for lash adjustments outside of spec...you can safely go .008 either side of spec. Lash loops...opening/closing lash is worth power/ET. Looser maybe be harder on the valvetrain depending on the cam profile.
http://www.harveycrane.com/lashloop.htm