in las vegas, you get snow. and cold. so your
plants won't survive totally outside all year unless you make some provisions for them. what i would do is move them outside to a porch or patio that you can create a "
green house" around then in the winter. either that, or cut them back (i do that a lot...) i cut my draceana marginatas back about once every 2 years and
plant the cutting. sometimes i give the cutting away, and sometimes i just keep it. they will also survive some amount of "root boundedness" and you can also root prune them.
the palms are a different story. i don't know hwat to tell you about them.
