intrepid70,
Now that you've described the storage yard problems in a little more detail, there are some possible explanations.
Was the storage yard that unexpectedly filled with barley set to "accept" barley for even a brief instant (as in the default setting, which is to "accept" all non-food goods)? If so, the barley farm cart pushers probably headed to that storage yard. If the storage yard was set to "not accept" barley when they arrived then they would deliver the barley there. (If the storage yard had been set to "accept 1/4" barley, then they would have delivered at most 800 barley. Even better, of course, would be to set the special orders appropriately before the storage yard gets labor.)
The cart pusher with flax standing outside of the storage yard was probably that storage yard's cart pusher. As you indicated, he delivered the flax to a weaver when he could, as he should. There isn't any problem, unless you want him to do something else. In general (there are exceptions), a storage yard shouldn't contain more than one good that could be "gotten" or delivered.
There's one thing to add to VitruviusAIA's explanation of merging 1x1 houses. Four 1x1 houses of different types will not merge. A square of four 1x1 houses will merge only if they are in a location that allows merging and only if they are the same type. (A square with a combination of 1x1 crude huts and vacant lots can merge, if the northern tile is a crude hut.)