Sorry to hear about your bad experience, I know how off-putting it can be.
But I wouldn't want to see you miss out on what I know from personal experience are among the best production EDC folder available, just because of an unidentified problem, or cause thereof.
I have 15 Spyderco folders, 5 of which are S30V including a Para2. I have never had edge problems like you describe here and show in your pics.
Occasionally a
new factory S30v edge may get tiny chips in it seemingly easily with initial use because of the way they are sharpened. I had that happen on my Manix XL when new, though nowhere near as bad as your pics show. After re-profiling and sharpening it, that has never happened again, and that Manix XL has been used a lot in the last few years.
Spydercos S30V blades, in my experience, hold there edge well in all sorts of cutting use. So what you have described here is raising an alarm to me.
The G10 on my Spydies is very durable, it will not wear away at the edges without the use of an abrasive or many many many many hours of handling. That yours has, based on what you've said, sounds another alarm to me.
I have had stiff opening on a couple of new Spydercos, never gritty, just stiff. Sometimes use will break it in, sometimes a
very tiny adjustment of the pivot screw is needed.
I have heard of people buying a genuine knife, putting a fake in the box and returning it to the seller, who can then unwittingly sell it on. Not saying this happened to you, but it's not impossible.
Better pics of the thumb ramp jimping, lock area and close ups of the G10 would help us see if it's a fake or not, though some fakes are getting to be to damn good and hard to spot, at least to my amateur eye.
Here's a few pics for you to compare. Note the backwards angle of the thumb ramp jimping.
May I make a suggestion? Go to the trouble of mailing it to Spyderco, with a letter outlining your issues. They will positively identify if it is genuine or not for you. If it is a fake, you'll know what the problem is.
If it is genuine, they may well fix your problem for you.
The list of BF recommended dealers is where you should shop for knives.