yes, becouse it is a grass tipe
No, Cradily can only learn Giga Drain through the Move Tutor in Humilau City from the Black 2 and White 2 games. You can always transfer one to Pokémon X and Y by using the Poké Transporter and Pokémon Bank apps.
Roselia learn giga drain at 25 before evolve to roserade.
No. It can't learn Mega Drain but it can learn Giga Drain.
100
Level 25
lv 51
giga drain
From my experience, you cannot find or buy the move Giga Drain In Pokemon Emerald. It is only a learned move. If you have a Shroomish, it will learn Giga Drain in one of its advanced stages.
In Generation IV, Sceptile can be taught TM19 Giga Drain. In Generation V, only Treeko can learn Giga Drain at level 46. Treeko evolves into Grovyle at level 16 and Grovyle evolves into Sceptile at level 36.
No. Cradily only evolves from Lileep at level 40.
If your gloom had mega drain then it evolved vileplume should still have mega drain, all though maybe it can't learn mega drain i do know it can learn giga drain.
Yes, Vileplume can learn Giga Drain. In Pokémon games, Giga Drain is a Grass-type move that Vileplume can acquire through leveling up or by using TMs in various games. This move allows Vileplume to not only deal damage to opponents but also recover some of its health based on the damage dealt. Always check the specific game version for the move's availability.