Installing dura ace 7710 crankset- quick questions.

First time installing an octalink set of cranks and I fear for their safety. Any tips or things to watch out for? Also, should I buy a torque wrench or can I just use a regular Allen key?

Torque wrench(es) is a great investment if you're a building up, stripping down bikes often, essential for any carbon parts or delicate tubing. You'll need around 40-45nm for the cranks. Most other small parts will be 4-8nm.
If not worth investing in, just get your lbs to torque them up for the first fitting and every once in a while check with an Allen key that they are not loosening.
If you ever feel a little bit of slipping during pedalling. Stop. The steel splines on the bb will shred the alloy tapers and render cranks useless.
Oh, and check crank arm alignment, easy to get one or two teeth out.

Thanks a lot for the advice b'jammin. Ended up popping them into my lbs as I probably don't do enough building to justify the expenditure. Currently working at Hearhrow so my lbs is a little place near terminal 3 (Heathrow cycle hub). If anyone lives or works near there I highly recommend them. Super nice and they put em on at 45nm totally gratis!

Will keep checking em for play anyways though just incase.