(Please note that this answer is for any future searchers and I came across this post while looking for answers myself)
I have been searching into a similar dilemma-- I basically wanted a minimum UI for install but to be able to customize the UI for an uninstall/repair.
I have found it is easiest to just create a custom UI for the process, It's as simple as including a new .wxs file in the project and putting using the following code;
(In your main .wxs file - inside the product tags)
<UIRef Id ="WixUI_MyCustomUI" />
(In the newly created WixUI_MyCustomUI.wxs)
<Wix xmlns="http://schemas.microsoft.com/wix/2006/wi">
<Fragment>
<UIRef Id="WixUI_Common"/>
<UI Id="WixUI_MyCustomUI" >
<TextStyle Id="WixUI_Font_Normal" FaceName="Tahoma" Size="8" />
<TextStyle Id="WixUI_Font_Bigger" FaceName="Tahoma" Size="12" />
<TextStyle Id="WixUI_Font_Title" FaceName="Tahoma" Size="9" Bold="yes" />
<Property Id="DefaultUIFont" Value="WixUI_Font_Normal" />
<DialogRef Id="ErrorDlg" />
<DialogRef Id="FatalError" />
<DialogRef Id="FilesInUse" />
<DialogRef Id="UserExit" />
<Publish Dialog="MaintenanceWelcomeDlg" Control="Next" Event="NewDialog" Value="MaintenanceTypeDlg">1</Publish>
<Publish Dialog="MaintenanceTypeDlg" Control="RepairButton" Event="NewDialog" Value="VerifyReadyDlg">1</Publish>
<Publish Dialog="MaintenanceTypeDlg" Control="RemoveButton" Event="NewDialog" Value="VerifyReadyDlg">1</Publish>
<Publish Dialog="MaintenanceTypeDlg" Control="Back" Event="NewDialog" Value="MaintenanceWelcomeDlg">1</Publish>
<!-- Greys out the 'Change' button on MaintenanceTypeDlg -->
<Property Id="ARPNOMODIFY" Value="1" />
<Publish Dialog="VerifyReadyDlg" Control="Back" Event="NewDialog" Value="MaintenanceTypeDlg" Order="2">Installed</Publish>
<Publish Dialog="ExitDialog" Control="Finish" Event="EndDialog" Value="Return" Order="999">1</Publish>
</UI>
</Fragment>
</Wix>
I can comment things line by line if you need more clarification but I recon this should solve your problem.
Basically you're creating a UI without any dialogs for your install- so the UI will default those properties from "WixUI_Common". The installer will function similarly to what you describe in your post.