Sagrilarus wrote:
1. Do I need to declare war on Spain prior to landing on one of their territories?
Unless you're allied with Spain, yes. You can't enter spaces controlled by another power unless you're at war or allied.
2. In a two player game (Spain and Ottomans) are Austrian positions in play as neutrals? There is a leader on one of their positions so my guess is yes, but I want to be sure. If so, do I need to declare war on them prior to going after their keys or fortresses?
I'm not familiar with the 2p setup, but my guess is "yes". The normal rules are that minor powers are still powers, so they need to be in a state of war or activated/allied by you (or one of your allies) for you to enter those spaces.
Note that "Independent" spaces (grey markers) are not subject to this, you can tromp in there anytime. However, once someone controls them you'll need to fall back to "are we allied or at war" to enter.