correct me if i am mistaken but if i am correct GC's self damage is fairly much concerned with the melee damage that you inflict since it count as still as neutral while the magic counterpart is holy (which is dealt with using the skill faith). thus that is the main reason to have lower str. therefore there is not really a reason to have holycross any higher than required for GC.
i play shield bash sader switching between elements to defeat monsters but guard is very useful especially when taking on mobs and also provoke fairly much reduced defence of target to nothing so that should be good for GC since your main concern is just explosive damage, though you must remember that they get stronger which is a problem when they do hit.
and yes GC paly is very strong mainly because of that additional 20 points they can spend on other things such as defense skills.
endure i am not quite so sure about since if you aren't really fighting magic attack type monsters i don't think they do anything other than allowing you to move while hit.
one of my old leveling spot was pnomena (i think i got that right, the hydra looking one that moves) with defender, they barely do damage, but killing them without elemental weapon is nasty.
When someone calls you a lunatic and the first thing that came to mind is a cute, fluffy, white bunny, you know you've played too much RO.
