My eyes kind of glaze over when I hear about hexidecimal editing. It may be so simple a monkey could do it, but it makes me feel like a four year old in an advanced calculus class. My brain just goes into "ignore" mode. I'll let DDStranslation handle the hex hacking. I don't know anything about pointers for individual character lines. (The script editing program that I use automates the entire process.)
The best I can do (and I often do this) is overwrite a nearby NPC's line (temporarily) with a formatted line that I can't view in context, make the appropriate edits, and then put the lines back in place... However, this won't work for lines that work in odd ways, or for windows like this that have movable cursors, since I won't be able to see or move the cursor. That wouldn't be a problem if, as you said, I could make the game point to the right place, but my editor doesn't have that ability, and as I said, I'm not equipped to make whatever changes are needed to facilitate that.
There's no walk-through walls code in the game. Right now, DDStranslation has been working on getting the credits to scroll properly. Last I heard, he changed the movement (which was originally left-to-right) so that the credits now scroll from top to bottom, fading out at the bottom at the proper spot... The next step is to get the credits themselves to be displayed horizontally, from left to right, in the proper order.
Tonight, I've continued translating the manual, and I've also updated the in-game item descriptions to be more helpful (using a very thorough Japanese guide for the game), so the player won't ever need to consult a guide to find out what special effects the weapons and equipment have. The original Japanese "descriptions" don't really give you ANY useful information about most of the items or skills! (It doesn't make sense for the scrolls, especially, considering that the hermits tell you what each scroll does when they give you the scroll - why would the description be "???" after you just heard the explanation!?) I've improved all of the necessary descriptions so that the player will always know what effects weapons, armor, accessories, scrolls, or skills have, if they have any. (For items without special effects, only the item's full name will be displayed. In the case of items with icon abbreviations to fit in the small font, the description window will always show whatever the fully-spelled-out name is.)
The English version will be much easier to play than the Japanese version because of this.