Ive taken kingfish upto 22kg using 8kb mono on an Okuma Oryx, this is virtually the same reel you are looking to use. Allot of it comes down to the angler, over sand you can run a light drag providing there is no foul around, youve got all day.

On the cheeper reels in the past, like the Oryx, I button off the drag and use my hand on the spool. It gives me a good feeling of what the line will take before it breaks and this way I know the drag is not going to stick or be the reason i lose the fish.

When using cheep gear, the worst thing you can do is load it with heavy line and set it to sun set. One of the reasons expensive reels are costly is because the drag is much more robust and reliable in comparison to a cheeper reel.

Lastly, longcast spools are not ideal, but certainly do the job providing you don't over load them. Because the spool is so deep the shaft has to push the spool up quite high to lay the line. When fully extended, this is when the reel is at it's weakest point and you can damage the shaft under pressure. This will mainly happen though if you are using 15kg mono and above or braid as it over tests.

So, long story short. Your gear will do the job if you are up for it. But more expensive gear will allow you to make mistakes without it costing a trophy fish.

Cheers