I have a pain in left shoulder-arm, close to armpit.. not sure which preset to use. I don't know if its a nerve, or vein issue either. Generally speaking I am not sure how to identify to use Killing or Healing for lots and lots of the database programs.

1. I would use healing preset. Contact mode and I would use the following frequencies in addition: 4 Hz, 7.83, 13, 100, 114, 333, 786.

2.Bruce Stenulson had in his Manual a set of Hz called "Mickie's Magic Three" which were, in this order, 324 Hz, 528 Hz and 15 Hz

10,000 Hz was also a very popular frequency for general pain application.

\Stenulson's machine was restricted to lower Hz so, you could also try octaves that are higher if those aren't helpful.

I'd look at Meridian Charts to see if the pain is in an Acupuncture point that is related to an Organ, which may be "acting up."

Which from my viewing the points, it looks like it could be your Gall Bladder. Points GB22 and/or GB23

3.I can't say, what you should do. 
Other members might add their ideas.

I hope you meant a few hours using Remote!
For "a few Hours" for Contact would be overdoing it. TENS uses Pain "Blocking" by fatiguing the muscles. That is not the best for "healing."

With Acupuncture Meridian Points, you could even stimulate them with a Pulsed or Constant Low Level Laser.
Almost any Hz "Could" be used on the point.Only trying it will you Know.

Look over the Meridian diagram closely as the there are other organs near that zone you mentioned, like the heart which is more "under" the armpit.

Chinese medicine calls "inflammation" congestion. You wrote "constriction."

FSM Frequency Specific Microcurrent might be a perfect therapy for your neck issues.

It uses a very low current level that is not even perceptible. 
Using an Avazzia or Scenar device, you set the current until you just barely feel it, then turn it down until that feeling just disappears. 
THAT is the level that works. 
Under the range of 600uA and much less. Probably at least 50uA

Overall, sometimes enlisting a Professional Practitioner, would be a wiser choice than experimenting on your possibly damaged neck.

4.Admittedly, I don’t have any experience of using Spooky to heal physical problems like Shane’s, but I would contend that other types of therapy are more appropriate. Shane, it’s possible that your problem could be resolved with just a tennis ball. By this, I mean put one under your upper back as you lie down and slowly roll on it, applying 10 seconds of pressure to every painful spot on either side of your shoulder blade. The trigger points you’ll find are MAJOR when it comes to pain in the shoulders, arms, and hands, and releasing them can end such pains in no time.

Not many people know about trigger points. Do an image search to get a quick idea, and if it looks like it could be for you, consider ordering the book, The Trigger Point Therapy Workbook THIRD EDITION, and a Thera Cane.

5. Maybe this help, when you pressure this points more times daily: Yanglingouan Gb34, Taiyuan L9. Best is, using a tool.

For more details, please check the link:
https://www.spooky2.com/forums/viewtopic.php?f=18&t=8545