the how-to is EM ready (tested with the version of phpBB2 that is documented in the how-to.
and should work with version higher than this - though not tested by me.
your firste qestion, should you change all 3 places - no, if it is only mentioned 1 time, you should only change it one place....witch to change ?
The how-to should be carried out in order, this mean you start at the to of the file, and do the steps according to this order - you should this way find the correct place to change the code....
your 2. question:
I have looked into this, and by looking at the code, it seam like phpBB2 have had a slight preformance improvement (adding the else in front)
it really doesen't mater for the functionallity, so you may run the how-to as it is, or (preferble) change it to leading "else"
#-----[ REPLACE WITH ]------------------------------------------
#
else if ( $group_info['group_type'] == GROUP_CLOSED )
{
if ($is
.
.
I will keep the how-to as it is, as it should be backwards compatible with older versions of phpBB2, and still work with the newest...