Looked into the shop issue with Inventory Manager. Chrono Trigger has valid data for 0x18 shops (00-17), but treats 0x40 values as shops with the special dialog command. Since shop data is just a list of item numbers ending in 00, pretty much any data in the ROM works in the shop code. With my testing just now, I loaded a shop that sells nothing and a shop that sells White Rocks for 2G each.
Also looked into stat cap adjustments. The original code had two checks on maximums, one for the menu, and one after battle. The menu code had unique values for each stat, while the after battle code checked all stats to see if they exceeded 99, and if they did, capped them there. It then had a final check to see if speed exceeded 50, and capped that as well.
This seems to indicate that speed originally was going to grow naturally, and had a limit of 50 instead of 10.
I also found a couple bugs in Warrior Workshop, so I'll squash those and add a speed growth/individual stat cap soon.