It's always safe to keep things in the fridge.

You need to figure out why most of the pickles didn't seal though. I'm assuming it's not chipped rims, and now Ball says you don't need to put the lids in hot water before using, so maybe you're not putting the bands on tight enough? Or wiping the rims (maybe a dill seed caught under)? This table doesn't list it as a cause of a porr seal, but maybe too much headspace?

If you describe your process maybe someone here can help.

And yes, in vegetables and low-acid foods like insufficiently acidified tomatoes/sauce/pickles, botulism spores can form toxins without popping the seals or showing any sign/smell of spoilage.

Here is a link that might be useful: NCHFP Troubleshooting table