Two Questions
The first question relates to configuration and print accounting variables. Both are accessible from Workspace > Configuration... (the latter after doing a File > Print). The descriptions of those variables will be in the Description area of the Configuration dialog box after you select the respective configuration variable.
For the second question, it is unclear if you are looking to change the filename as opposed to using the exact filename. For the latter, you might want to take a look at using:
"$(basename(_DGNFILE)).LRG"
for your default_outFile... statement in the PLT file you are using.
BTW, it might be better to post one inquiry per thread... we have found that makes it easier to follow (and find) specific topics.