While I def agree with most of what you say, lack of defense is what hurts them WHEN they play better teams. It ends up being a shootout, unless you are feasting on rookie or back-up QB's. This years D was a casebook of they played awesome against the teams the should have (JAX withstanding) and they struggled a bit with the playoff teams.
Don't get me wrong - I am ALL over more weapons and better O-Line depth. Just like a "get home" DL or DE is a priority.