Q1: Can the Main effect of this card be activated at the same time as an effect that digivolves, such as "P-103 Offense Training"?
No, you cannot. The Main effect cannot be activated at the same time.
Lv.- Calumon BT19-077 R Unknown | Unknown | Unknown [Security] You may play 1 Digimon card with 2000 DP or less from your hand without paying the cost. [Main] By suspending this Digimon, 1 of your Digimon may digivolve into a Digimon card in the hand with the digivolution cost reduced by 2. [All Turns] This Digimon can't attack or block. [On Deletion] Place this card as the top security card.
Lv.- Calumon BT19-077 R Unknown | Unknown | Unknown [Security] You may play 1 Digimon card with 2000 DP or less from your hand without paying the cost. [Main] By suspending this Digimon, 1 of your Digimon may digivolve into a Digimon card in the hand with the digivolution cost reduced by 2. [All Turns] This Digimon can't attack or block. [On Deletion] Place this card on top of your security stack.
Lv.- クルモン BT19-077 R 不明 | 不明 | 不明 【セキュリティ】自分の手札から、DP2000以下のデジモンカード1枚をコストを支払わずに登場できる。 【メイン】このデジモンをレストさせることで、自分のデジモン1体を手札のデジモンカードに支払う進化コスト-2で進化できる。 【お互いのターン】このデジモンはアタックとブロックができない。 【消滅時】このカードをセキュリティの上に置く。