Here are some things that I found.
Genis-Vell's powers:
FlightPretty self-explanatory; he can fly and travel at high speeds, even in outer space.
Cosmic Awareness
Allows Captain Marvel to sense danger on a universal level. As a result, he can perceive objects and individuals, the presence of beings, and cosmic threats cloaked by invisibility or illusions throughout the universe.
Illusions
Captain Marvel is able to manipulate light and project it as illusions.
Photonic Energy
Captain Marvel can absorb and channel cosmic energy stored in specialized enclaves within his cells. The Nega-Bands allow him to fire it off as energy beams, to use it to form protective shields, or many other abilites.
Telepathy
Captain Marvel and Rick can communicate with each other telepathically. They can also see what the other person is seeing through their eyes.
Vectoring
Performed by focusing on a particular star, tracking into the light to use it as a guide and travelling beyond its speed. Adjustments have to be made, otherwise he'd track the light back to its source and end up in the past.
Nega Bands:
Nega BandsThe Nega-Bands convert psionic energy stored within Captain Marvel's cells into increased strength, grant him increased resilience, the power of flight, the ability to fire beams of energy from the bands, and the ability to survive unprotected in space. They also allow Captain Marvel and Rick Jones to switch places between the Microverse and the regular universe
Resiliency
The Nega-Bands grant Captain Marvel increased resilience and the ability to survive, unprotected, in outer space. He can also breathe in environments that contain no oxygen.
Super Strength
The Nega-Bands can convert cosmic energy into increased strength, allowing him to lift roughly 15 tons under optimal conditions.
Some better ones:
Super-StrengthCaptain Marvel has super-strength. His strength level, which can be enhanced by focusing energies of his nega-bands inwards, may be anywhere from class 15 to class 50.
Power Source: Both Physical ability and Negabands.
Flight
Captain Marvel can fly and travel at high speeds, even in outerspace. He can breathe in environments that contain no oxygen. (However, he cannot breathe in water, because there is oxygen -- and he just can't extract it, as seen in Captain Marvel #2)
Power Source: Negabands.
Cosmic Awareness
"Cosmic Awareness" is the power to be cosmically aware of his surroundings. Right now, Rick and CM have no little control over the Cosmic Awareness, and it is contantly on.
Power Source: Physical ability
Photon Blasts/Cosmic Energy
Captain Marvel can fire beams of Photon energy from his nega-bands. PAD also said at the Captain Marvel Message Board: "My feeling is that the energy he funnels through his negabands can be used in a variety of ways. He can direct it internally, giving him accelerated strength. Or he can manipulate it to form the equivalent of energy "shields" to give him some insulation against attack. Think of it as cosmic shock absorbers. If Marvel was just standing there, offering no defense, and the Hulk hit him, they'd be picking up the pieces from here to Saskatoon. As it is, in a fight he was able--through quick action with the negabands--to deflect/absorb some of the impact. Some, but not all."
Power Source: Negabands
The Nega-Bands
Rick Jones uses the negabands to switch place with Captain Marvel by slamming them together and he is replaced by Genis-Vell (Captain Marvel).
The nega-bands also are like a funnel of energy, giving Marvel a lot of his un-natural powers.
In Captain Marvel #3, Genis (while Rick was in the realworld) was able to cause the negabands to release a powerful Jolt of energy. However, Rick Jones cannot tap into the Negabands full energy potential, but can release energy Jolts into someone if they come in contact witht he bands.
Power Source: Negabands
The "Exchange"
Rick Jones and Captain Marvel are molecularly bonded. Rick switches places with him using the Negabands. When one of them is in the real world, the other will be in a "nullfield" which protects them and keeps them immoble. This nullfield is found in the microverse. In Captain Marvel #4 & #5, Captain Marvel broke the nullfield when he transported Drax to the microverse with him, so while one is on Earth the other is free to roam the Microverse. And they fell to the alien planet K'ai. This is where Hulk first met his green-skinned alien lover, Jarella.
Power Source: Negabands, and the fact that Rick Jones and Captain Marvel are "missing" Atoms, and they need to be connection to survive.
Mental Connection
Rick can speak to Captain Marvel (and vice versa) via some unknown mental connection, and they see each other's reflections instead of their own.
In Captain Marvel #15, Captain Marvel was able to concentrate and "enter" into Rick's dream, and wake him up by mentally creating an image of him banging symbols together. This leads to suggest their mental connection may be closer than previously thought. Whether through concentration Rick can do this as well, or this ability is uniquely Genis' remains to be seen.
Power Source: Physical Ability
Spatial Aperture
Genis at one point was able to create spatial apertures with his nega-bands. It's a hole between the universe and the nega-verse, it kept whatever was trapped in the aperture in a stasis field. Unable to move, but able to talk and listen. Since Genis' connection to the negative Zone is seemingly gone(to what degree, I do not know) it is unclear if he still has this ability.
Power Source: Negabands.
Energy-to-Mass Conversion
This isn't exactly a power of his. In Captain Marvel #16, a freak accident causes Captain Marvel to turn into living energy, and using his Nega-Bands he was able to reform himself. However, he cannot do this naturally himself, or at least not yet, maybe eventually when he learns more about his powers.
Power Source: Both Physical ability and Negabands.
And here is the site I found the better description from. Should answer lot of questions about Capt. Marvel.