There's a few threads on this in other sections covering this on specific classes.

Our boat have always had the centre sheeting option (coming from the A class) and I have always used this system and swear by it.

On the CAP we have 2 different boom sections to deal with the mid loading. But just like Jake said it is no more that you can pull (this is little over 50kg). Most of the load is still at the end of the boom.

The tramp reo is some heavy Dacron sewn to the underside with some over sized washers on the block saddle.

it's a pretty easy system to set up... figure out where you want the block on the deck, find a good sail maker to put some reinforcing patches into the tramp. Measure the distance from that to the mast base. That will be the the distance from the goose neck to the hanging block on the boom.

I'll see if I can find some good images of it and I'll sketch it up if you guys want.