🚀 go-pugleaf

I have spent a day scouring the groups for the answer to this problem
but have been unable to find it, so, I will ask the question and
please accept my apologies if it has already been answered.

I am trying to create an Application Server (exe) that will allow
multiple clients to connect and will allow multiple synchronous
requests.  That is, if client 1 connects and starts a long process,
client 2 does not have to wait until the long process has finished
before they can process their own requests.

The groups contain lots of similar questions but I cannot find a
conclusive solution.

1) Is the above caused by the fact that the AppServer is an EXE and
thus all requests run in the main thread (of which there is only 1)?

2) If I create the server as a DLL instead, will the problem be
solved? and if so,
   i) How do I set security on the DLL (because I can't then use
dcomcnfg)?
  ii) Do I have to have a surrogate process in which to host the DLL?
 iii) Can (or should) the surrogate process be MTS?
  iv) How easy is it to convert an EXE AppServer (>20000 lines of
code) into a DLL AppServer?

It would be fantastic if there was a setting in BCB that solved all of
this for me but as there isn't, what is the best approach and what
questions should I be asking when deciding to build an EXE or a DLL
AppServer in the future?

Sorry to ask so many questions in a single post.

Thanks for any help in advance.

Andy