Crossbow

Are you trying to control torque or limit it?   Buffer mode is set on the second instruction, the one interrupting the active axis.  MC_TorqueControl only supports abort and buffer, not blending.  It is for applications controlling torque directly, like turning a screw or a bottle cap.  I suppose it can be used that way with the InTorque output, but it's purpose it to maintain a specific torque at a commanded speed, not to indicate a torque level. You could also run a velocity movement and simply do a compare against the current torque value (Axis.Act.Trq) for it to exceed your limit and trigger an MC_Stop then.

All depends on how your screen can communicate.  The PLC likely has some serial protocols, I am not sure which ones, as you never mentioned which Siemens PLC you are talking about.  What protocols can the screen use?  Does it have communication drivers to talk to Siemens? Serial communication is as diverse as the languages people speak... you need to make sure the screen and the PLC can both talk one language...

Pretty sure the device will only have one IP address.  I have used a wireless access point to a PLC in the past without issues.

Manual W506 covers the Ethernet port and has this chart in it.

The only document I could find on Lite indicated only NX1P2 and NJ101.  Would be nice if it was better documented.  

Nope, ladder font is fixed.  ST font can be adjusted.

Sysmac Studio Lite is only for NJ101 and NX1P2.

From the manual for the CIPUCMMSend instruction: Size specifies the number of elements to send. If ServiceDat is an array, specify the number of elements to send. If ServiceDat is not an array, always specify 1. If no service data is required, set Size to 0. The response data received later is stored in RespServiceDat. The number of bytes of the response data is stored in RespSize.

The PLCs are always backward compatible, but to get all the latest features, this should be set to match the version listed on the side of the PLC.

Why not use the PLC to run the process?  They can do PID control too.  Seems like two controllers where only one is needed.

Comments are only stored in the CPU if the original programmer chose to download them.  So if they aren't there, you cannot upload them.

You never mentioned PLC or version.  The only reason I know that they would not show is the one brought up by IO_Rack, are you certain both projects have the correct firmware version selected?  Firmware is always backward compatible, so maybe 1.41 wasn't selected in one project.

And as I have said multiple times, those errors indicate the extension module FX2N-8AD you are using is not communicating with the PLC.  Of course you will get an error when they are not connected.

You should really perform the automatic update on your software.  Current version is 1.46, you're a couple years behind.

The last several messages here explain how to do it.  Did you read it before posting?  What more information do you want?