Just a heads-up for SMB3: VFP is completely capable of SMB3. I have a customer with a clustered Hyper-V Server (i.e two identical boxes in parallel mode), running a VM with my DBF files as a regular fileserver-share. That's a Restaurant-System in 24/7 mode; i.e. those DBF files are always in use. The HyperV-server does his routinely updates and occasionally reboots and then switches the VMs from one machine to the other without interruption of the SMB3 connection, even though the other box has (of course) a different network card, IPs etc. Just for testing, I tried to run a Client with SMB1 only connection and got plenty problems with lost connections and dataaccess troubles.
SMB3 is vital and necessary for all modern Windows Server operations, don't shut that off or you will get killed by some admin. SMB1 is not needed anymore in todays worlds.
As long as you have local (Client) DataCaching and OpLocks disabled, everything is ok. In your VFP EXE at startup check those Registry keys from Christof's list, and yell if they are wrong. No, you can't change them from inside your EXE, since those are machinewide settings and therefor require AdminRights.
wOOdy