Basically I just wanted to confirm that the installer resize weirdness was confirmed when using the mouse.
I used the Mouse completely where applicable on all but the last of the installs because even at 1024x768 resolution all controls on the SolydXK Installer Screen were completely visible and had no issues at all and it was like any other normal install. (Which is why I made the comment that I don't see your issue as a VMware issue per se.) I did the last install in VMware Player under Ubuntu Linux predominantly using the Keyboard just to test and collect the steps I posted because in your OP you said "Any ideas for a workaround?"! 
The Mouse was always installed and available in all the installs I did and is necessary to assign /dev/sda2 device to root (/) on the Partitioning screen. I do not know why you are having an issue since it installed just fine for me and as expected in three different VMware Products under three different OS Platforms. Also I tested at higher resolutions and even higher then 1920x1080 however I used 1024x768 because anything less then that the buttons across the bottom of the SolydXK Installer Screen were 99.9% not visible.
I'm assuming that after the install the mouse works as usual? Didi you happen to get a chance to install the Tools.
Yes the mouse worked fine during the Live OS session, the SolydXK Installer and the installed OS running from the Virtual Machine. No I did not install VMware Tools, no time to because of wanting to test on multiple platforms and VMware products and also I don't intend to use SolydXK as OS X is my preferred Unix/Linux type of OS.