Re: Need some advice
Define 'security'. I mean the an Access database on a computer not connected to the outside world would be super secure. One on a local network isn't far off. Of course in every case you still could have a disgruntled employee come in and set the place on fire or delete records. So, what are you concerned about security-wise?
You would never make more than 1 backend. That method you are thinking of is 1 backend and multiple-front ends. That method might speed up your database, but it would actually be less secure (more doors to your house, more ways for criminals in).
My advice would be to pick specific goals and work towards them. What you've asked of us is pretty vague and I am unsure you even know what you want.