If he just mimic-ed the FF that Super-Skrull has than he would definitely lose. Super Skrull has been fighting the FF and using that exact power-set for his entire existence (as in first comic appearance not actual character life). He is a trained veteran Skrull warrior and would mess mimic up if they fought on those terms.
plus Mimic only have about half the stength of who powers he has assimulated.
but if he absorbs the powers of
Proteus
Proteus is a being made out of psionic energy, and as a result he possesses many psionic abilities. He possesses telepathic abilities, the ability to possess human bodies (eventually, these human bodies "burn out", due to the nature of his powerful energies), and powerful reality-warping powers - able to practically change the face of the world by pure force of will. For example, he can easily turn a standing building into liquid, turn buildings into bees that attack at his mental command, and transform Cyclops' optic blasts into flowers. Proteus' main weaknesses was to metal, such as a bullet entering his host body or, to a greater extent, when his energy form came into contact with the organic metal of Colossus' body.
Doop
Doop's body contained a nightmare dimension called Doop Land, which he could access by turning himself inside-out. He had roughly Class 100 strength and an untested level of energy projection, which included the ability fire energy blasts from his brain and the power to emit a short-range energy pulse that prevented psychic intrusion. Doop’s body contained a backup brain, which could sustain him for a short period of time in the absence of his primary brain. Having no legs, Doop moved via levitation. He could inflate his body to unknown proportions. The full extent of Doop’s many powers is unknown.
Darkstar
Psinic interface with the Darkforce dimension grants her various powers, including flight, teleportation, concussive force beams, and the ability to create solid constructs composed of Darkforce energy
Scrambler
Scrambler is a mutant who possesses the ability to disrupt the function of any system with his touch, whether that system be that of a living being, a machine, or a field of energy. Scrambler must physically touch his target with his bare flesh in order to affect it. Scrambler has at least partial control over the effect his power has. If he touches a living being, Scrambler can cause immobilization, unconsciousness, or death. If his victim possesses superhuman powers, Scrambler can disrupt the function of those powers, most often causing them to overload which is often traumatic or even fatal for the victim.
he would be damn near unstoppable . with this powerset he would stomp a mudhole into Super Skrull.