Hi Eric
Congrats on your first smoke! WRT the smokey flavour, the point of reference should be what you like

Couple of pointers, first off, always, always go to 200F or further with pork shoulder if you want it to be tender enough to pull. Any less and the collagen doesn't break down enough to allow the meat to fall apart. It looks to me like the lower half of your joint was ready to pull but the top half needed longer. I've gone as far as 212F before (accidentally) and it was the best pulled pork I've ever made.
Smoke ring - whilst pleasant, and a good sign the smoke has penetrated the meat well, it isn't everything and the proof is in the eating! It does make me wonder whether charcoal aids the process of creating the smoke ring at all?
Leftovers - if you chuck it in a pan with some thin sauce (like NC vinegar sauce) you might be able to get it to the point of being able to pull. If you don't have / like the NC sauce, a little apple juice or cider works well too.
Some ideas for pulled pork leftovers (no good for slices though):
-Top pizzas off with it (best added hot post-cooking)
-Plate of pork with mac n cheese
-Baked potato topping with beans
-Yet more sandwiches
Finally, you mentioned probes. If you are gonna get into this, you essentially have a couple of options - buy a cheapo probe for about £20, and struggle along, or splash £40 (amazon) on a Maverick. Being able to monitor the temps, indoors, without touching the smoker, makes smoking more pleasant, easier, reduces cook times and gives better end results. Well worth it if you ask me.