What kind of plant is this?

The sellers left us a lot of potted plants, mostly outside on the upper patio but also scattered about the lower patio, driveway, and dining room.

Who abandons their plants like this?

Most of them are mysteries to me.  We have a house rule that all plants that come indoors must be non-toxic and hard to kill.  Otherwise they live (and probably die) outside.  So it's pretty important that we figure out what these are and re-home them if they will be problems.

What is this?

It is about 4' tall.  It has several large trunk-like things.  It probably wants a bigger pot because this one is a little deformed from the trunks pushing out. 

Leaves do this.  They are thick and heavy.

It makes flower buds.

 Also: is this toxic?  Is it winter-hardy? Do you want it?