Maybe you don't mind to live along with certain frustrations like some of my customers  , but I do  . The following few tips could ease away some of your frustrations:

Case 1) Importing an assembly of parts come into SimXpert as one part.  Ouch! Please don't go back and go through all the effort to export each part individually and importing each part individually again! That must be plain painful!

Answer 1) Tools > Options > Geometry - CAD Import: Tick "Create a Part for Each Body" 

Case 2) Importing a rather large (sometimes not even large) CAD file takes unreasonably long 

Answer 2) Tools > Options > Geometry : Increase the Tolerance values. Low values create beautiful round curves and surfaces but need a lot more GPU power to update the view and this is done for each part during the import process. Relax these figues (higher values) for a faster import and decrease them for nice screen prints of zoomed in areas. 

Case 3) You have setup contact bodies and setup a contact table but the job does not run or its evident that the contact is ignored! 

Answer 3) After creating a Nastran Job, in each loadcase (in the model browser), pick the contact table that should be active (since there can be more than one in the model for different scenarios) in the LBC Container (Right-click and select "Select Contact Table") 

Case 4) When using Touching contact (and Tet10 elements i.e. quadratic elements), the contact does not resolve and the job does not complete 

Answer 4) Under the Analysis Solver Control options: Contact control Parameters - Contact Separation Parameters: Set Separation Criterion to "Stresses", not "Forces".  The problem is that quadratic elements like Quad8's and Tet10's can have negative residual forces on their midside nodes when the total element edge force is actually positive. This is thus not a good measure to use when resolving contact.

Case 5) You select RUN under an analysis to submit the job to Nastran, SimXpert display "Argument 2: prog=simxst" and then nothing happens. You even went away, came back and still nothing! 

Answer 5) "Argument 2: prog=simxst" is displayed after SimXpert successfully submitted the job to Nastran for analysis. Unfortunately SimX does not monitor Nastran's progress. If your were lucky, and simply went ahead to attach results (because the video tutorial said to), you might be able to do so if Nastran was quick enough to complete the job before you tried to attach it. If it is still busy, well, you might not realize this and wonder why you have no results.
So, how do you monitor Nastran's progress? Simple. Open the .F06 file (it will have the name of the job you chose and the extension F06) but open the file with a small free utility like WinTail or BareTail which opens and updates the bottom (newest) lines of this text file constantly.

If you open the .F06 file with Notepad, you will only see the content of the file at the time you opened it - it won't be updated until you close and reopen the file.

If the analysis takes a while, you can follow the progress by looking at the new lines added to the .F06 file. The job is only done when it says: "* * * END OF JOB * * *"

Then, just to check if the job was successful, search for the word "fatal". If Notepad or Baretail can'f find it, then the job was succesful. If a fatal error is found, you have to read up about it and fix it before there will be any results to look at.

Case 6) The .F06 file is rather large and I only use it to check for errors. I also find that it takes very long to update with results values of displacements and stresses etc.

Answer 6) The default setting is to reflect all the requested output results in this text file. With large models, this process can sometimes take longer than the actual analysis! Under each loadcase, double click the requested output to edit it's properties and tick "Suppress Print". Then the results not be printed in the .F06 file in so much detail and you will get access to your visual results much quicker!

If I think of something else I'll add it here.