Possible dangers of home fermentation of vegetables I bought this FARMcurious Fermentation kit on Kickstarter. Once I got it and started making it I found their claims of it being "super easy" were a little exaggerated. When looking around online I found that other people recommended weighing your salt instead of measuring by volume and that it absolutely did matter what kind of salt you used (so I rinsed the veggies off and started over).

I started them fermenting in August and was supposed to check them in October. Well, it's now January and I've just been too afraid to try them.

There is no mold growing, they've been in a dark room in my basement. The airlocks are all intact. Nothing "looks gross". I opened up one that had cucumbers, carrots, and celery in it and it just smelled vaguely "pickly" (not bad at all). I tasted one and it was just sort of soft-ish and very salty. It's been 2 hours and I'm not dead or sick or anything.

My question is... What are the dangers here? How would I "know" if it "didn't work" or if it "went bad"? This person tested PH and looked at it under a microscope. What would I look for exactly (I happen to have the exact same microscope)? What would happen if they were bad and how long would it take to happen (if I ate some)?

Most stuff I've seen online claims that if it were dangerous it would smell so bad you couldn't even eat it and that this is the absolute most safest method of preservation.
Fermenting vegetables is a pretty safe procedure, in fact, if done properly, fermented veggies are probably safer than raw.  Really, little can go wrong if handled properly.  The process is literally thousands of years old.  In fact, your biggest concern is contamination after the process is complete.  Of course you need to use safe food handling procedures to begin with (clean product, clean hands, clean containers...etc).  Then you need to use the proper level of salt for the product you are fermenting--2.25% by volume up to 13 or 14% depending on the vegetable.  The idea is to bring the product to a pH level of 4.6 or lower. Basically, using the correct amount of salt, at the correct temperature, for the correct amount of time achieves this.  There are lots of online resources.  Probably the foremost expert on ferments is Sandor Katz.  He has an excellent book and an informative website.

If you can verify that your product was handled correctly (cleanliness, salt, temperature, time), there should be no reason that it is not safe.