First of all - welcome to the wonderful world of catamaran sailing!

The mast should lean back as far as it can go - leaving enough space between the boom and rear crossbar to fully sheet in the main sail. Given that you've got an older boat, you probably have the stock mainsheet blocks (two blocks on the boom; a double block stacked on top of the ratchet on the traveller). That and the short forestay are going to limit how far back you can rake the mast. Put the side stays in the bottom hole of the adjusters and see if you can hook up the forestay when you step the mast. If not, add another adjuster to the end of the adjuster attached to the bridle. A piece of bungee cord tied between the two adjusters will take the slack out when you tension the rig with the jib halyard.

There is no screw adjustment in the shroud adjusters - you just have the different holes to work with.

The two holes on the mast step link are to accomodate both the Hobie 16 and the Hobie 14 (the same part is used for both boats). Use the one furthest out (it should have a "16" stamped next to it).

Good luck!