So the Psyker can do anything he could normally do with his hands. Does this mean that he can affect/manipulate more than one object simultaneously? Say a ballistic shield and an autogun?

I don't think so. Unless mentioned otherwise, I'd consider telekinesis to always be one object only, although one could possibly debate whether the psyker could "drop" one object and switch the power to another one.

I've looked into this a little more closely, and there doesn't seem to be anything in the RAW that directly limits the number of objects you can affect with the Technique. However, that said, the Technique _does_ have an effective Strength Bonus equivalent to its Psy Rating; I assume this would dictate the total number of things that could be effectively manipulated with the power in the form of weight.

For example, a Shield weighs 3 kg, an Autogun 3.5 kg, a Missile Launcher 12 kg and Heavy Stubber 35 kg. With a Psy Rating of 3 a Psyker could have the Technique 'Carry' up to 9 kg, 'Lift' up to 18 kg, and 'Push' up to 36 kg. This would enable the Technique to only 'Push' the Heavy Stubber, or a combination of the Shield, Autogun, and Missile Launcher (total weight 18.5 kg), 'Lift' the Missile Launcher and either the Shield or Autogun, and properly 'Carry' the Shield and Autogun. Any of the objects being lifted, dragged or carried could be subject to manipulation in the form of trigger and pin pulls and the like, which I assume would require the normal time necessary to operate.

I will bring this up in the errata thread for official clarification.