Q1: Can I use this card's On Play When Digivolving effect to suspend my Digimon?
Yes, you can. This effect doesn't specify a player, so you can specify either player's Digimon as the effect's target.
Q2: If I specify my suspended Digimon for this card's On Play When Digivolving effect, can I resolve "if this effect suspended your Digimon" effects?
No, you can't. Even if you specify an already suspended Digimon as the target for a suspending effect, it isn't considered to be suspended by the effect.
Q3: If Raid switches the target of attack from a player to an opponent's Digimon, does the Your Turn effect in this card's inherited effects trigger?
No, it doesn't trigger.
Lv.5 GrandGalemon ST18-10 R Ultimate | Bird Dragon/Vortex Warriors/LIBERATOR [On Play] [When Digivolving] Suspend 1 Digimon. If this effect suspended your Digimon, you may play 1 Digimon card with [Avian] or [Bird] in any of its traits and 3000 DP or less from your hand without paying the cost. --- Inherited: [Your Turn] [Once Per Turn] When this Digimon attacks your opponent's Digimon, this Digimon may unsuspend.
Lv.5 GrandGalemon ST18-10 R Ultimate | Data | Bird Dragon/Vortex Warriors/LIBERATOR [On Play] [When Digivolving] Suspend 1 Digimon. If this effect suspended your Digimon, you may play 1 Digimon card with [Avian] or [Bird] in any of its traits and 3000 DP or less from your hand without paying the cost. --- Inherited: [Your Turn] [Once Per Turn] When this Digimon attacks your opponent's Digimon, this Digimon may unsuspend.
Lv.5 GrandGalemon ST18-10 R Ultimate | Data | Bird Dragon/Vortex Warriors/LIBERATOR [On Play] [When Digivolving] Suspend 1 Digimon. If this effect suspends your Digimon, you may play 1 Digimon card with the [Bird] or [Avian] in one of its traits with 3000 DP or less below from your hand without paying the cost. --- Inherited: [Your Turn] [Once Per Turn] When this Digimon attacks your opponent's Digimon, you may unsuspend this Digimon.
Lv.5 グランゲイルモン ST18-10 R 完全体 | データ種 | 鳥竜型/ヴォルテクスウォリアー/リベレイター 【登場時】【進化時】デジモン1体をレストさせる。この効果で自分のデジモンがレストしたなら、自分の手札から、特徴に「鳥」を含むDP3000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。 --- Inherited: 【自分のターン】[ターンに1回]このデジモンが相手のデジモンにアタックしたとき、このデジモンをアクティブにできる。