Is it possible to use same order twice with Thrawn?

For example Two CC dials. ONE from The ship and second one from Thrawn Magic order. Does it give me two additional dices to the dice pool?

Same situation with engineering Command. Do I get joined pool of engineering points (for example 4 from ISD) and if I take taskmaster on board do I get twice his effect?

No.

From the latest FAQ, page 5, under Commands:

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A ship may only resolve a command by spending one command dial, one command token, or one command dial and one matching command token.

And from the Rules Reference, page 4, under Commands:

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A ship cannot resolve the same command more than once per round.

So you can't resolve two of the same Command Dials in the same round.

That said, it doesn't say you can't spend two Command Dials in one round. So I'm guessing you could use one Dial to resolve a command, the other to do something else - although note that many Command-related effects only apply when a Command is revealed - and the Thrawn Dial is gained, not revealed, so you'd have to use the main Command Dial for that (this includes removing Raid Tokens, using Taskmaster Grint and so on).

You could also spend the main Command Dial to turn it into a token, and combine that token with the Thrawn Dial (again, you can't token the Thrawn Dial because it isn't revealed ).

For Taskmaster Grint, even if you could use him on the Thrawn Dial as well as the main Command Dial (which you can't), he still wouldn't give you 2 tokens as you can't have more than one token of each type at once.