Q1: When I use this card's Main effect to place up to 4 of my Tamers with different colors under 1 of my Susanoomon as its bottom digivolution cards, what areas can I choose Tamers from?
From the battle area. When text doesn't specify an area, it means that it specifies, references, or affects the battle area.
Q2: Can I use this card's Main effect to place 1 of my red and blue Tamers and 1 of my red and yellow Tamers under 1 of my Susanoomon as its bottom digivolution cards?
Yes, you can.
Lord of Devastation and Rebirth BT18-096 U Ten Warriors While you have a [Hybrid] or [Ten Warriors] trait Digimon, you may ignore this card's color requirements. [Main] 1 of your Digimon or Tamers may digivolve into [Susanoomon] in the hand or trash without paying the cost. Then, by placing up to 4 of your Tamers with different colors as 1 of your [Susanoomon]'s bottom digivolution cards, gain 1 memory for each placed card. --- [Security] You may play 1 Tamer card with inherited effects from your hand or trash without paying the cost. Then, add this card to the hand.
Lord of Devastation and Rebirth BT18-096 U Ten Warriors While you have a [Hybrid] or [Ten Warriors] trait Digimon, you may ignore this card's color requirements. [Main] 1 of your Digimon or Tamers may digivolve into [Susanoomon] in the hand or trash without paying the cost. Then, by placing up to 4 of your Tamers with different colors as 1 of your [Susanoomon]'s bottom digivolution cards, gain 1 memory for each placed card. --- [Security] You may play 1 Tamer card with inherited effects from your hand or trash without paying the cost. Then, add this card to the hand.
Lord of Devastation and Rebirth BT18-096 U Ten Warriors While you have a [Hybrid] or [Ten Warriors] trait Digimon, you may ignore this card's color requirements. [Main] 1 of your Digimon or Tamers may digivolve into [Susanoomon] in the hand or trash without paying the cost. Then, by placing up to 4 of your Tamers with different colors under 1 of your [Susanoomon] as its bottom digivolution cards, gain 1 memory for each placed card. ---
破壊と再生を司るもの BT18-096 U 十闘士 特徴に「ハイブリッド体」/「十闘士」を持つ自分のデジモンがいる間、このカードは色条件を無視できる。 【メイン】自分のデジモン/テイマー1体を手札/トラッシュの「スサノオモン」にコストを支払わずに進化できる。その後、色の異なる自分のテイマー4体までを自分の「スサノオモン」1体の進化元の下に置くことで、置いた1枚ごとに、メモリー+1。 --- 【セキュリティ】自分の手札/トラッシュから、進化元効果を持つテイマーカード1枚をコストを支払わずに登場できる。その後、このカードを手札に加える。