"I also noticed the more complicated and short the code is the more you get chance for errors."

Yes!
It is a common misaprehension that making your 'C' code as terse as possible will give you more efficient object.
With a good, modern optimising compiler there is usually no advantage to cramming everyting into a single expression. It just gives you more chance to fall foul of unexpected side effects, operator precedence, etc, etc

eg, see Erik's comments in this thread:
http://www.keil.com/discuss/docs/thread1525.htm