OK, first of all.
Captain Falcon armor: He is NOT inmune to shots or laser guns. Nowhere in canon has it said that his suit is anything more than a racer's suit. It does not give extra protection. It is nothing more than a racer outfit.
http://fzero.wikia.com/wiki/Captain_Falcon#Characteristics
-----------
Second: electrolaser and paralyzer being the same.
You can say that the paralyzer its useless because it cannot harm the space pirates in the game but, think for a second and look at the power suit's standard attacks and the space pirates in the mothership.
Those pirates are red ones. The strongest kind of space pirate second only to the gold ones, as shown in Super Metroid and Metroid Zero Mission. They have superior weaponry and armour. They are the elite of an extremely advanced race that has technology proven to be more than a match for the galactic federation they are fighting against.
Hell, even Metroid Prime 3's strongest breed of Pirate is red:
The only thing shown to be a match for that armour is a beam that can pierce through anything, has an infinite range, shoots 3 blasts per shot and freezes the opponent completely.
This is more a case of the pirates and the power suit beams being extremely broken, not a case of the paralyser being super weak.
http://en.wikipedia.org/wiki/Electrolaser
And this brings up the potency of the electrolaser. It is basicaly a taser taken up to eleven. It will jam your electronic weapons (Falcon's futuristic blaster), it will completely paralyze Falcon if he survives the blast and the bullet is as fast as a lightning. About 96% of the speed of light actually.
And you can shoot it whenever you want. You don't have to stand still to use it.
---------------
Third:
No, the captain's muscles realisticaly would not let him move as fast as he does in Brawl. It is not realistic.
http://tvtropes.org/pmwiki/pmwiki.php/Main/MusclesAreMeaningless
Proof:
Joseph Greenstein, known professionally as The Mighty Atom (and likely inspiring the golden age DC Comics character of that name, and Astro Boy's original name) weighed 15 pounds less than Bruce Lee did. His feats included changing a tire without any tools, biting through nails and chains, lying on a bed of nails with a 14 piece Dixieland band playing on a board on his chest, and stopping a plane from taking off by clipping it to his hair. He first became interested in developing his body and mind when a jealous suitor of his wife shot him at near point blank range between the eyes. The bullet broke his skin, but flattened itself against his skull.
Pictured above: The Mighty Atom.
No bodybuilder can do what he has done.
Some of his feats of strength included:
Pulling a 32 ton truck with his hair.
Holding back an airplane with his hair.
Lying on a bed of nails supporting a 14 person band on his chest.
Breaking up to three chains by expanding his chest.
Removing a car tire from its rim, bending steel bars, spikes and horse shoes, all with his bare hands.
Driving spikes into wood planks with his palm.
Bruce Lee was about 160 pounds at his heaviest, and slimmed down in later years. By his movie-making prime, he was about 135-140 pounds, 5'7, and could do pushups with a 250 pound man standing on his back.
This is because he opted to gain lean muscle instead of mass muscle in his training. Just like in the bodybuilder example, those large muscles are mostly for show and the smaller-looking man of similar weight is often the actual stronger one.
Tone>Bulk.