Any suggestions?
I've an old E6400 which gets used for testing once in a while. Suspend type stuff worked once in the past but never since I updated the firmware about 4 years ago. Solution = don't use old laptops with crap firmware as HTPC devices.
Display overscan is ideally solved by setting the TV to some kind of "Just scan" setting instead of forcing 16:9. If that's not possible you can go into Kodi and calibrate the screen output for each refresh rate that you will use; i.e. if you calibrate at the default 60Hz you also need to repeat at 23.98 (23.976Hz) and 50Hz (PAL 25Hz x2) etc.