The contractor ran about 100 feet of 1" grey schedule 40 conduit without inquiring what the needs were for this location. I need to pull two speaker cables 14/4 and a 16/4, one RG6, and three cat5 cables. I don't believe I have a chance. I am thinking 2 inch would be needed, with 90° sweeps at each end, and a couple 45s in the middle.

You should have specified the size.

Are you able to access any of the sweeps?

Test it on a ten foot stick with two 90 sweeps and a crap ton of lube.
You could strip the jacket off the speaker wire too.
This would all have to be pulled at once.

Shouldn't be a problem, providing you're using a lot of lube and possibly have access to at least 1-90 degree bend.

I would use plenum rated speaker cable as the jacketing is less material than your typical PVC cable. The RG6 will hurt you a bit.

Communication has been a little bit lacking on this project, otherwise I would have been prepared better. How much lube do you think it will take for this kind of run?

Better hope the inspector doesn't see it.  Code limits how full you can stuff conduit.

It should work if you have tight jacketed cat5 and you arent trying to use weird audiophile speaker cable that has way too much jacket.

Tape the cables up really well at the front, lots of lube and use your fingers to try and keep the cables all in line going in so they arent twisting around one another.

You can buy lube in quart bottles and larger. Lube the head of the cable well and keeps squirting it in the conduit as the cable is being pulled in. You can't have too much lube!

Is there already a pull string or a jet line in there?

Steel fish tape

This isn't true for Class 2 and 3 circuits and power limited fire alarm. This covers almost everything we do. NEC sections 725-3 and 760-3 basically tell you to disregard article 300 where conduit fill is established.

Pick up a cheap nylon rope to use as the pull. You can use it to prelube the conduit.

That's true and it's a real issue for power cabling, which gets warm. You might even get an electrical inspector on the job to ask him if there's any problem filling this thing up.

Definitely remove the speaker wire jacket and yes, this will all have to be pulled at once. Even if you have the room for another wire, you'd have to get the business end of a snake through there and it would interweave with the existing wires, maybe making a snag halfway through your pull.

Twist is indeed your enemy as twist results in a larger cross section.

Except when the inspector doesn't care and calls you on it.  It happens.

RG6 Plenum is smaller too. I have some if needed.

Is conduit under/in ground?

If so, that is considered a wet location.
I would use direct bury wire, or it will not last very long.

Where we are, even with Class 2 we're limited to 40% fill on a conduit. Stupid but it's the rules.