I usually think plants getting "stuck" like that, sitting there looking ok and not growing, is some kind of problem with the roots. I usually suggest you dig it up (for container plants that's really not hard, you can basically kind of slide it out of the container) and take a look at the root system.
People are always hesitant about that, but with a little care you can do it without harming your plant. If everything looks good just pop it back in. But you may find you have a nice healthy looking little plant with hardly any root system.
The large plant with the tons of blossoms is a different issue. IF it has had blossoms for a long time but no fruit, then I presume it is dropping the blossoms without setting fruit, called blossom drop. Blossom drop is a stress reaction. Peppers are pretty prone to it, especially when temps are above 90 or above 75 at night.