Exactly what I described in less alarming words. Steam, hydrogen, other gases, and "radioactive material" (Iodine and Cesium in the steam) are not the same thing or anywhere near as dangerous as actual melted fuel and corium escaping containment. Conflating this with the idea of molten core materials breaching containment is extremely irresponsible.
I'm not entirely sure about the radioactive water situation, and it sucks to hear that it may be worse than I thought. Do you have a source confirming the extent of contaminated water that ended up in the ground or ocean? It's really hard to find anything unambiguous here, tons of stories about "leaks" but many of those reports are actually about leaks into the reactor buildings. As far as I can tell a very large number (trillions?) of becquerels went into the Pacific Ocean right around the time of the tsunami, and since then no water outside the reactor complex has been measured with radiation levels outside regulatory limits (although they've been pumping groundwater collecting in the basements into big tank farms, like you said). It does look like the large volume of water pumped into the ocean initially (to make room for contaminated core water in the spent fuel pools, like I said) may have accumulated in bottom-feeding fish near the site. And it looks like there may be water from the site leaking into the ocean at some rate (although not enough to make any ocean water unsafe to drink). Other than that all I can find is an enormous volume of noise and fearmongering.