Looks like the start of Ca deficiency, if you sprinkle a few handfuls of garden gypsum on the top of your pots it will slow the progression and stop a few weeks later. Once Ca shows it just gets worse until you give them the calcium they want.
re: Questions On When To Buy Seeds & Storage
The seeds should be fine stored in a cool dark place for at least a few years, unless the seeds you buy are already years old.