Fantastic Four wasn't the first. Marvel has a long history of comics, and several series came before it. Different characters and storylines were introduced earlier that contributed to the Marvel universe's foundation.
The Fantastic Four is a Marvel property. Marvel created these characters and they have been a significant part of the Marvel universe for a long time. They have their own unique storylines and adventures within the Marvel framework.
Occasionally, Deadpool does show up in the Fantastic Four comics. Sometimes it's for a brief cameo, and other times he plays a more significant role in the storylines.
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.