I've tested Landstalker and I don't have the issues in your screenshots.
Some noob questions, are you running in PAL mode or with CPU Turbo?
Like I said, the text box issue has been fixed since the 0617 release.
Currently I can spot the issue when changing screens in form of status bar flickering(minor) and that sprites get drawn beyond the normal bottom frame. How this manifests can be influenced by the overclock where with normal settings there a two scanlines beyond the bottom border and (mostly) just one on high, medium lets the second scanline flicker.
I have tested this with with video modes 0 and 8 and for both with vsync_adjust 0 and 2.