Did you install from NeuroDebian or your Ubuntu/Debian distribution, instead of via DownloadPsychtoolbox or SetupPsychtoolbox? Then you should run PsychLinuxConfiguration manually once. It runs automatically as part of [Download-/Update-/Setup-]Psychtoolbox, but needs manual invocation when installing from NeuroDebian. That script will create the /etc/X11/xorg.conf.d/ directory and set suitable permissions, so XOrgConfSelector can do its job.
That understanding is wrong, at least on current Linux + X11 X-Server, as used by Psychtoolbox. I think macOS has that limitation, so if you are coming from there, that’s why you’d think that.
The mouse is polled and reported at most as fast as it asks to be polled. Typical desktop mice request 8 msecs / 125 Hz polling. Some gaming mice can ask for up to 1 msec / 1000 Hz.
The monitor doesn’t matter for that on Linux + X11.
We have a test function HIDIntervalTest to allow to check the polling rate. Also MouseMotionRecordingDemo to show optimal mouse movement recording on Linux, and with more limited reliability on Windows, but not on macOS.
Please buy a (help PsychPaidSupportAndServices) community membership with priority support to support PTB ongoing maintenance, development and support. Any further advice or comments from my side will require that anyway.
Best,
-mario