automechanicar, you didn't mention which solver you were using... To really perform an impact such as a drop test, you'd want to use SOL601 or SOL701 in NX Nastran, do you have access to these modules? If not, you could perform a dynamic response, but you'd have to manipulate the data a bit...
bdf stands for bulk data file, it's just an extension... As far as nastran is concerned, the extension doesn't matter as long as the input file is in the proper nastran bulk data format...
Basically, the syntax to manually submitt a job with nastran is: nastran <filename> <option1> <option2>...
NX Nastran "basic" would be SOL106, probably the weakest of the lot (except for Mechanica), as you pointed out you'd need the advanced non-linear, SOL601, to perform surface-surface contact, although you might be able to get away with gap elements.
Both Abaqus and Marc would definitely do a...
If you're running NX Nastran 32-bit, you should be able to assign about 1.3GB of RAM on Windows, and maybe 1.5GB on Linux, but not more... With NX Nastran 64-bit, things get much better since you can assign 8GB-10GB easily...
For a model like this, I would definitely use the elemental...
Which solver are you thinking of using? Forming might need a more specialized code than a generic non-linear code like SOL106 (I'm thinking Abaqus, LS-Dyna, Marc or Adina).
My first guess would be a units mismatch, i.e. the force you are applying is not correct... The large mass method should work just fine and should give similar results...
Both MSC and NX Nastran cover as much, arguably even more if you think about DMAP programming. The surface-surface contact in NX Nastran is pretty darn good, and is not limited to statics, it is also able to deal with modes and dynamics response... All the NE animations can definitely be done...