It sounds like your trying to fix all your woes and run an entire environment from a single machine. Personally in your position I would consider virtualization and attempt to create several small virtual machines in order to facilitate your needs. I've had great success with Proxmox virtualization , they also provide turn key linux servers to accomplish exactly what your trying to do. It's important to learn how to use linux, but if your wanting to get up and running fast, there is no better way I have found than to just run Proxmox and turnkey linux virtual machines for the applications I need. They have prebuild filesharing servers as well as a PDC server, and a TigerCRM server. Please read up on them and see if that would be a good fit for you.
Here is the link for the proxmox server software, this will install a complete virtualization solution in one disk , keep in mind this will WIPE your hard disk
and install this software http://www.proxmox.com/products/proxmox-ve
Also you can install directly form Proxmox turnkey linux servers
Here is a link to the turnkey linux distro and how to use their prebuilt canned linux machines.
Keep in mind this is just one route to go, considering the amount of things your wanting to do , its always better to just virtualize and keep seperate servers for seperate tasks.