Good Morning Kind Sirs:

Am I correct that this line here is calling the TMF but also opening a trade at the default lots and specified limit price?

enterShort (MyTMF, 0, -5*PIP);

Sorry if it seems basic but I need the sanity check.

Thank you

Not correct. Look at the definitions of the functions:
https://zorro-project.com/manual/en/buylong.htm

You just required that your TMF have two arguments. It must be:

function MyTMF(var v0, var v1){ /* ... */ }

In your case, v0 will be 0, and v1 will be -5*PIP for that particular trade. I do not think that this is what you wanted.

You can still set parameters such as Lots and Stop prior to placing the trade, but not as function inputs.

Thanks Andrew. You are right, I was not intending to pass any argument to the TMF. Yes, I was wondering if I could specify trade entry parameters as well as make a call to my MyTMF in one single command.

Thanks, I will continue to set them separately.