Those aren’t actual bugs but incorrect rulings of cards for the 2004 format:
(I was advised to post them in the bug reports section of the forums, so if it’s not the right place to post them I’ll delete the topic if needed)
Steven’s advice should work even if you have 7 cards in hand, and stops being playable when your hand size exceeds 7 cards.
Double rainbow energy applies -10 damage AFTER weakness and resistance, unlike metal/darkness which have their multipliers applied before weakness and resistance.
In a similar note, Strength charm adds 10 additional damage AFTER weakness and resistance.
Those cards had their erratas applied after the world championships and the rotation of Expedition, aquapolis and skyridge. (Oct 1, 2004 PUI Announcements) And since the cards were played as they were printed,
Decks from EX-HL are fairly inconsistent as they are and changes like steven’s/double rainbow (strength charm too to an extent) are impactful to them, so I’d absolutely recommend to apply their old rulings for the format instead, since they were played like that back then.
The format has some other weird erratas but I haven’t playtested it enough to point them now.
Thank you for your attention!