Answers to your questions ....
1) Most of the EXE and DLL files get rebuilt each time we make a new shipment of the product (whether they need to be or not -- it is done as a part of the automated VM-build process). The exceptions include the emsrv.exe, the messgae DLL (emsrvmsg.dll), and the library access DLLs (emntv50.dll and emsrv50.dll) -- these are built in a separate way and have not been rebuilt since May 2002.
2) There is no reason I can think of to have 2 copies of emsrv.exe running. One copy can support the largest number of concurrent users I have ever seen (over 200).
3) uninst.exe is called from the Control Panel Add/Remove Programs to do the actual work of uninstalling, so you did the right thing.
4) Each release of VA Smalltalk (7.0, 7.5, etc.) is independent of other releases. This means that you can have 7.0 and 7.5 running side-by-side on the same machine with no problem. It also means that the 7.5 manager install will not update a 7.0 manager (in part because they have different names and in part because the install process is quite careful not to installl a new manager over an old manager). For point releases (7.0.1, 7.5.1, etc.) the installs are NOT independent if an earlier install of the same release is found on the machine (based on registry entries). Point release installs will update the existing installed code and will merge the new manager into the old manager). You can still run point releases side-by-side since the directories that must be different have the release number as part of their name. However, some things (like the shortcuts and the contents of directories not having the release number as part of their name) do get replaced on each install.
If this is still unclear, let me know.
John O'Keefe [|], Principal Smalltalk Architect, Instantiations Inc.