Haven't had any of those issues with mine.
I did have graphical issues in 3.9 where mine would corrupt some of the screen and moving icons looked corrupt but this was a setting in 3.9 not the indivision.
Prefs/Workbench and change "store icons in" from "other memory" to "graphics memory" all crisp as an RTG render.
Most of the faults I've seen/read have been a software setting in 3.9. Not sure what OS you are using?
I'm currently using highgfx on my 24" Dell monitor which is reporting 50Hz with the indi ii.
Had a 4 hour gaming run last weekend with my son playing super methane brothers, got warm but no over heating and no glitches. Oh I had to ditch the standard PSU and now using a 350W ATX PSU, mainly because of the all the mods but made the machine really stable.
Will be going back to a PICO PSU once I get a new one after killing the old one with some old dodgy A500 expansion I found :-(
