In some comic arcs, the Skrull can be seen as bad due to their actions and motives. However, there are also instances where they have more complex and nuanced roles.
Definitely not. Rhodey's character in the comics was never depicted as a Skrull. His role and development were consistent without this element of transformation.
The Marvel Cinematic Universe was a very large fictional world with many powerful superheroes. The answer to the strongest might vary from person to person. Some people might think that batman is the strongest because he has super physical fitness and superb skills and can use all kinds of weapons. Some people might think that Superman is the strongest because he has superhuman strength and speed and can use energy weapons. Some people might think that Thanos was the strongest because he had the Infinity Gem and could control the universe at will.
However, there were many powerful superheroes in the Marvel Cinematic Universe, and each superhero had their own unique abilities and characteristics. Therefore, there might not be a clear answer to the strongest.