Printing issues are known but should be possible to work around with 
short printer names and removing unneeded "printers". Other than that, 
Paradox should run fine on Windows 10 and what you see is not normal.

When it comes to printing there ar major differences between Paradox 9 
and 10. P10 and P11 are "the same".

There are some issues with some builds of Pardox, for detailed 
information see:

http://hem.bredband.net/bertilisberg/paradox/versions.htm

I have P10 and P11 installed on many computers in my office and at 
clients sites, often on brand new Windows 10 machine without any major 
issues.

I never see any need to do a custom install, just run the installation 
with admin rights and start the app with the o-switch to a custom config 
file and you should be fine.