Yeah about that the problem is that in mid air there is a slight second where he feels like he is floating in midair i want him to come down the moment he gets there, also i want the jump to be really fast.
Increasing the effective gravity will make jumps faster in general. If you don't want higher gravity for other objects, an extra acceleration could be applied to the character body specifically by adding (0, -extraAcceleration * dt, 0) LinearVelocity each update.
If you want a very specific custom behavior, then yes, you'll need to apply appropriate forces.
He doesn't get stuck but he does stay there for a second before recovering from the fall.
Does 'stay there for a second' imply you cannot control the character? If so, that doesn't sound normal. There might be some configuration issue (scale, perhaps) or geometry issue. If you can reproduce the behavior in the latest BEPUphysicsDemos for me to look at, it could help.
If the character is still controllable throughout but the body just takes a fifth of a second to fully 'stand up' again, that's more expected. The speed of the depenetration could be increased using the CollisionResponse.MaximumPenetrationRecoverySpeed (that's a v1.3.0 name- I think it may be 'Correction' instead of 'Recovery' in v1.2.0).