SmartFTP Remote Control & Command Line / Multi-Part Transfer Settings

Good Morning!
I've got 2 questions - one of which has really been bugging me.  If I could get any answers, I'd be very appreciative...
Question #1
I currently use SmartFTP on my home "server" to make various downloads throughout the day - all of which mostly come from the same remote host.  Every time I want to do this, I connect via RDP to my home server, open SmartFTP (if not already open,) refresh my source, select files, and start.
Is there a way - even via command line - that I could perform these tasks remotely without viewing the remote server's screen?  Even if it's just as simple as starting and stopping the queue, that would be enough for me.
Question #2
When adding items to the queue, here's the process I follow:
  1. Stop the queue (if running) 
  2. Add files / folders in order I want them downloaded
  3. Select all objects in the queue, right click, properties, Advanced tab
  4. Enable Multi-Part Transfers and set to 10 (I only use 1 worker) - Apply
  5. Start Queue
My question is that in the favorite's settings, there's one additional setting:  File Size Threshold.  What is that exactly?  Does it mean that all files below that size do not use what I have set for Multi-part?  If so, what do they use? 
Thanks Guys!