Thanks for the feedback, Calatar. Since Archon did so well answering your other questions, I'll field these:
Calatar said:
Every hex you move into prompts an encounter though? That seems excessive, unless the hexes are made much bigger. The PCs would never be able to explore the whole island if they had to fight monsters every few feet. Maybe they're not supposed to, but I'd personally get tired of monsters if I had to explore an island made up of hundreds of hexes full of monsters.
I could see this becoming an issue, especially if you look at every encounter as a combat exercise. I tend to look at encounters as possible parlay situations, sightings, etc. The frequency of encounters is intended to allow for more interaction with the adventure (even if that interaction's just evading a potential threat).
If you choose, feel free to change it up a bit. We're talking "old school" gaming here - these are guidelines, not rules, so feel free to change the adventure to suit your tastes.
I'd recommend at least a 50% chance per hex of having an encounter, though - otherwise the adventure's in danger of becoming little more than a sight-seeing trip.
You could also make some of the encounters "interesting" by twisting them in different ways. For instance, what if those randomly encountered ants are guarding an anthill? What's down there? Look at encounters as chances to improvise and embellish, not necessarily fights waiting to happen. It's a sandbox - feel free to play in it.
Calatar said:
1/4 movement speed penalty means the player gets 75% of their speed or 25% of their speed?
A character's movement rate should be reduced by 25% of the character's movement score. (Example: a character that normally moves at 60' per turn moves 45' per turn.)