Luminen Shock does 1D10+3 Energy Damage with the Shocking special ability.

Since it's a melee attack, is the Strength bonus added to the damage total?

You have to spend a half action per turn to sustain Maglev Grace/Transcendence.

Is this wether you move or not, or have you to, in order to actually move, invest the other half action as the Rogue Trader Rulebook seems to imply?

Thanks

Do you add your strength bonus to Luminen Shock?

The rules is worded as, "The Luminen Shock deals 1d10+ 3 points of Energy Damage with the Shocking quality" I It does not say anywhere that it is a melee attack in the mechanical sense of the phrase, only that you use WS for the talent. Since the source of the damage is energy, not impact, I would leave the strength bonus off.

Is your half action sustain for Magvev G/T separate from any move actions?

"The Explorer must employ a Half Action each round to maintaining the rite, and may use the other actions to move normally." The wording here is fairly explanatory. The half action allows you to continue hovering. If you want to move, that takes another action.