I agree it would be great to get some official documentation from Hobie. While you are waiting on that, I can provide some information since I did this install earlier this year.
For #1, I used this info posted by RHoughVYC:
To insure full hoist on the Hobie 16 Spinnaker when used on a Hobie Getaway the top of the sheeve should be 6865mm from the bottom of the mast extrusion. Measure this from the joint between the mast step casting and the mast up to 6865mm (22ft 6.27in). The actual placement of the tang will depend on the block and shackle you use for the halyard.
*Note* The dimension on the instruction sheet is for a Hobie 16 and is too low on the mast for the sail to hoisted completely.
For #2, the pulleys go on the front cross beam. The ratchamatic blocks go on the shroud anchors.
There is a very nice installation document written by OttawaDave. He sent me a copy and I have been meaning to update it based on my experience. Let me know if you are interested and I can send you the document.
The spinnaker is a great upgrade, unless your mast breaks.