A full ROM map and other FE5 docs by Zane can be found at https://feuniverse.us/t/fe5-general-doc-nightmare-modules/3735

006B28: Unit names (moved from JP rom), see 'names.tbl' for syntax

0146D9: Start of prologue text (cut off in-game and it's also mistranslated)
014721: "together with his loyal knight Fin"
01482F: Where prologue actually starts

02CFF0: Config menu (uses names.tbl syntax)
02D07C: unused text?
02D10A: unused text?
02D1EC: Audio settings
02D244: unused text?
02D254: unused text? (same as 02D07C)
02D280: Pointers for the RGB thing
02D28E: Red
02D749: Config menu continued

031931: "Cliff"
031935: "Plain"
0319B1: "Road"
good luck fitting these into 1-2 characters

05340C: Shop text

08CBA0: world map code, looks like

0F5D74: Inventory Screen tilemap

0AA49F: Chapter 1 script
0513F0: seems to be related to chapter 1, but idk if the dialogue is here necessarily - maybe event scripting
2DC520: In the Search for Victory ~ Base
354000: Portrait pointers?

38FA80: Battle Forecast tilemap ("Attack" starts a little lower)

The script uses a compressed font, see script.tbl for details

HOW TO EDIT THE INVENTORY SCREEN AND BATTLE FORECAST

The text for the Inventory screen and battle forecast is tilemap-based. Your best bet is to open the game in Mesen-S and seek to the part you want to edit, then click Debug > Tilemap viewer. Right-click on the tile you want to edit and View in Memory Viewer (make sure to set it to a monospace font so it displays properly). The first bytes from your cursor is for the tile you selected. If you copy the first two bytes (or a few more to be sure) and Ctrl-F them in a hex editor, you can (maybe) find them and edit them. From then on, just compare the codes of various tiles to figure out which tiles you want to go where. You can also edit the tile live by changing the byte in the Memory Viewer itself.

The Inventory screen at least has some rhyme and reason to it, starting at around 0F5D74. The battle forecast, at about 38FA80, is especially scrambled, so finding the tiles individually in the Memory Viewer is probably the way to go.
