Can vmware (virtualisation) configuration impact the data integrity of the data file I'm wondering how much can a VMWare configuration impacts the integrity of the data file.

I mean, if the VMWare configuration is not optimal and the database writes a lot of complex operations (creations / modifications / deletions).

Can poor performances and bad configuration of the virtual machine, that host the database, lead to a potentially corrupted datafile when the the application is solicited a lot in read/write operation?
Your question doesn't contain many details so I'll treat it as a hypothetical question.

Combining data and log files, or any other type of files shouldn't lead to corruption in .vmdk's any more than it would on a normal disk.

You haven't specified which RDBMS or OS you are running, and maybe some obscure systems exist where combining data and log files on the same drive causes the files to become corrupted but I would consider that a bug in the software and it would happen just as well with physical drives.

The VMWare knowledge base contains some documented corruption issues, but none of them have anything to do with combining certain types of files or write operations on the same vmdk.

If you have actual corruption things that come to mind are issues with vmotion or old veaam versions in combination with large backup sizes, but not combining certain files.