Legends that are only so on the back end are not included - so Sidequest: Hunt the Mark /// Yiazmat, Ultimate Mark isn't included, nor is the melded form of Ragnarok, Divine Deliverance though it is referenced on its constituent cards
Playing the Overlord on three will put you at four lands that turn, and if you have another land drop on your fourth turn, you can cast another Overlord for the full five mana, as a creature this time, while further ramping you to six lands
Extended borderless cards are legal and fully playable in any magic tournament

Adventurer's Airship Adventurer's Inn Aettir and Priwen Balamb Garden, Airborne Balamb Garden, SeeD Academy Baron, Airship Kingdom Blitzball Buster Sword Capital City Clive's Hideaway Cooking Campsite Crossroads Village Eden, Seat of the Sanctum Elixir Excalibur II Forest Genji Glove Gohn, Town of Ruin Gongaga, Reactor Town Guadosalam, Farplane Gateway Insomnia, Crown City Instant Ramen Iron Giant Ishgard, the Holy See Island Jidoor, Aristocratic Capital Lindblum, Industrial Regency Lion Heart Lunatic Pandora Magic Pot Magitek Scythe Midgar, City of Mako Monk's Fist Mountain Plains PuPu UFO Rabanastre, Royal City Relentless X-ATM092 Ring of the Lucii Sharlayan, Nation of Scholars Starting Town Summon: Bahamut Swamp The Gold Saucer The Masamune The Regalia Treno, Dark City Ultima Weapon Ultima, Origin of Oblivion Vector, Imperial Capital Wastes Windurst, Federation Center World Map Zanarkand, Ancient Metropolis
The other Sliver I have a lot of respect for is Taunting Sliver
Boldwyr Heavyweights Borderland Explorer Edge Rover Fall to Earth From the Ashes Hired Giant I Call on the Ancient Magics Jace, Architect of Thought Jungle Wayfinder Krenko's Buzzcrusher Natural Balance New Frontiers Noble Benefactor Path of the Animist Rathi Fiend Rootweaver Druid Ruin Grinder Tempt with Discovery Travel Through Caradhras Urza's Sylex Veteran Explorer Wave of Vitriol Weird Harvest