Confirmed

Garrus - Armor Piercing Ammo

Garrus - Proximity Mine(unlocked 2nd)

Liara - Warp Ammo (Note: This is different than Liara's bonus power in ME2)

Liara - Stasis

James - Fortification

James - Carnage (unlocked 2nd)

EDI - Defensive Matrix

EDI - Decoy

Ashley - Inferno Grenade

Ashley - Marksman (unlocked 2nd)

Kaidan - Barrier

Kaidan - Reave (unlocked 2nd)

Tali - Energy Drain

Tali - Defense Drone (unlocked 2nd)

Javik (From Ashes DLC) - Slam

Javik (From Ashes DLC) - Dark Charge

It appears that every squadmate has 4 active powers. Two of them are availiable to one of the six character classes as a baseline skill. The other two will become availiable to any class as a bonus power.

The Chakram launcher should be available to you immediately. Once you find the first weapon bench you should be able to select it under the list of available assault rifles. Alternately, if you find a weapon during a mission, you can choose to change your loadout and equip the weapon that way.

If the weapon isn't showing up, it might be that it wasn't unlocked. In order to unlock the Chakram Launcher, you have to get to the end of the 45 minute timed segment of the Kingdomes of Amalur demo.

The Reckoner Knight armor should be available once you return to the Normandy after the Citadel section. If you go to the armory, there is an area that allows you to change your armor. The second slider down allows you to select the Reckoner armor.

Regarding your EA accounts, no additional linking should be necessary as long as you're playing with the same account/console that you played the demo on.