Mum's the word

We planted mums a few years ago to give our garden some fall color and all but 1 of the 4 have come back, to some extent at least.

What I find strange is that these autumn plants themselves came up very early in the year - probably in April or May looking very healthy and happy. But when they finally bloomed last month, they developed some kind of split personality complex - only flowering on half of the shrub. Here is the same mum, taken from two angles:

 Here is mum number two, again from two sides:

They seem to prefer blooming on the shady side of the plant. Could it be wind or other weather related? Is there some kind of fertilizer I should be using or something else I can do to make them more consistent?

This other plant is "technically" alive, though it is so puny that its future doesn't look good. See it there? Those two tiny white flowers? Yeah, that's a mum too.

We have another mum ready to join its brethren outside after our fall centerpiece gets dismantled (which is really soon because we already had to get rid of one moldy pumpkin since this picture was taken and I'm sure more are on the way). I'm so bad at seasonal decorating - except for Christmas - so this was at least a small attempt to make the table a little more festive.

Finally, while we're on the topic of autumn plants, can anyone identify this tree? It's in our neighbor's yard and I love it! Such vibrant reds! Not that we have any place to plant it, but it would at least be nice to know what it is.