You don't need else logic in what you are doing in the example I posted above you would just have the else section do nothing.

What I posted above does the exact same thing, in the same order as your logic, it is just much smaller.

So, to show it again this time with the else's in there.

if(system power, false)
-----delay 3.0
else
-----
var system power =true
alias TV-HDMI2
delay 0.1
ALIAS receiver-dvd
if(system mem, false)
-----delay 0.1
-----alias audio 3-left
else
------
jump media center

What this says is:
If the power var is set to false add three seconds.

The next four commands are executed regardless of what "system power" is set to.

One the next if, we are adding the delay and hitting the left arrow

Then the jump media center happens no matter what.