I don't have my wiring diagrams and notes with me, but I can get them for you later today. Until then, this is what I do recall.
You can find VSS at one of the connectors behind the kick panel on the driver's side of the car. It is down low, just below the carpet. I'll get you the color later.
The easiest place I could find for the reverse signal was behind the trim panel above the rear deck on the passenger side. The same signal runs to the rear-view mirror, so you could pick it up there if you would rather.
You can get to the delayed accessory turn-off power at a connector behind the rear trim panel over the rear deck (passenger side). This is the power that doesn't turn off until you open a door after turning the key off. The accessory power wire at the radio connector goes off as soon as you turn the key off. (The factory radio was doing the delay function internally.) This does not apply if you had factory navigation. In that case, the correct signal would already be there.
There is a good location for the GPS antenna at the center of the rear deck. If you take the rear package shelf trim off, you can put the antenna on the metal bracket below it, and it will be completely hidden. The factory location for the factory navigation GPS antenna is under the dash behind the message center buttons. I think that some duct-work has to come out to get to it. I think the rear location is easier.
I'll get you the wire colors later.