Ok, let's double check a couple of things.
For the decoded journal, another member had the same problem as you, but here's what they said fixed it: "I tried hitting the enter key after deciphering each page and that seemed to work to get the game to moving forward."
You might check again that the pages really are fully decoded and you haven't missed an odd letter here or there.
As for Bat Steep, did you check the glass display in the hotel lobby and learn about the different bat species? Here's what MaG's walkthrough says as regards directions:Bat Steep does not have a parking lot but a dirt path.
Take note that there are short cuts marked by tire tracks in the sand. Use them to see where they lead.
Take the top left road and go to Monkey Center, Bat Steep, Shark Cove, Blue Hole and then Sangre Beach.
Some reference points for you there.
And lastly, do be sure that you've read the book from the basket in the lobby from cover to cover, so that the game triggers that you have actually read it. Then see if you can get the dialogue with Johnny.