Miniboxes are a whole lot easier to clear through than main boxes. It saves more gems in the long run considering how much longer main boxes take to dig through unless you're lucky. I'd only recommend going after a minibox UR if there's still a massive amount of packs remaining and it's the only one that interests you. I personally spent mine on a 2nd copy of Gladiator Beast Gyzarius (I'm F2P).
Yes, I agree with that point. Pick a UR from the main box. Floodgate, Lance, Drowning, Cosmic Cyclone, Galaxy Cyclone, Fusion Gate, Divine Wrath, Night Beam are all good options.
Totally agree, only use it on main boxes. Mainly in old ones. Also not in a box you want to dig for extra cards. Cards that will always be usefull imo are:
Cosmic Cyclone
Gold Sarcophagus
Herald of Abyss
Floodgate traphole
Blackrose
Brioniac
Ancientfairy
Vermilion
Trishula
Fiendish Chain
Htg core theme cards:
Cyber Dragon/Twin
Black whirlwind
Dark Paladin
Invoked Purgatrio
Stratos
"Recommended for beginners" are like "Recommended to cheat beginners". Sorry for those who took White Stone of Ancients/Magician Navigation. You have wasted your ticket.