If the ringneck is under 2 years old then indeed the ringneck COULD in fact be a male.... they don't normally get their rings until they are about 2 years old, plus or minus a few months.
Here's a good comparison of a male and female lutino ringnecks...
As for DNA sexing, yes it does hurt to pull out a feather! Even worse for birds than humans, since a feather follicle is much larger than our hair follicles... And with pulling out feathers there is a small chance that the follicle could be damaged (which normally isn't really an issue unless it's with the wing and tail feathers... and it's more of an issue when they are pulled out the wrong way....)... nail clipping tends to be easier as long as you don't cut too far into the quick. If you do, use cornstarch or flour.
DNA sexing tends to be cheaper with
Avian Biotech than through a vet. There's also
AMR Labs which a breeder recommended... there are other labs out there that do DNA sexing but I don't know which ones are reputable and which ones aren't.
And if indeed Boss is a female, as long as you don't encourage breeding you shouldn't have to worry about eggs and chicks (although there is still a chance that it could happen). Currently with 5 cockatiels here... 4 females and 1 male, there may be some breeding going on however I haven't gotten any eggs since the cockateil family came here... and it was just one, and chronic egg laying stopped.
Only once have I not encouraged (in any way) breeding and egg laying but still managed to get a female that laid eggs... and it was resolved by putting her in a different cage. Thus normally, if egg laying does occur, it can be stopped by changing things around.