You may spend the two mana added by the last ability on the same ability or on two different abilities
You cant just swap basics between opponents and ruin their mana bases
, Sacrifice this land: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle
Flame Rifts play rate if the larger fortunes of the EDH burn deck in microcosm
At the beginning of the next end step, exchange life totals with that player, exchange control of all permanents you and that player control, and exchange cards in your hands, cards in your libraries, and cards in your graveyards
You could even take two different commanders that share a color, and build a larger module for each that allows you to swap between commanders while keeping the same base theme intact