i think the right way is:
echo ro.HOME_APP_ADJ=1 >> /data/local.prop
or edit /data/local.prop
and add line:
ro.HOME_APP_ADJ=1
to the end
Keeping launcher in memory is not an ideal (or a good) solution....basically what u r saying is that give launcher highest priority and never kill it...of course it wont have any lags but it will cause lags in other apps which now wont have enough memory to play with.