DLL Versions

In developing an application (VB6.0) and its setup program, we have had to deliver a couple of shared DLLs to get the app to work on the target. We're using InstallSheild 6.0, and we make it rename existing DLL's and copy our DLL to the same directory. This is Windows NT (soon to be my problem on Win2K, but I'm learning that's another story, however if you've got an answer that works on both OS's...)

#1 Is this an acceptable solution, providing we go to the MS website and download the latest DLL's before compiling our app and making our setup program?

#2 Along the lines of NOT replacing a shared DLL, is there a way to register i.e. MSMASK.dll and compile my .exe in a way that the .exe will point to that MSMASK.dll version? In other words, can you have multiple versions of the same DLL on a machine?

#3 General DLL question: If I have compiled a DLL, I know VB registers it. If I want to move it to another folder, is it necessary to use a DOS window in the current folder to regsvr32 /u the DLL, move it and then regsvr32 the DLL in the new folder? Is there another way to do this?

#4 Know any good articles that would explain DLL's from a developers point of view?

Thank you thank you thank you for anything. I can't wait to hear from you.