Minimum Unsatisfiable 3-CNF Formulae
Take the formula in your example, remove the clause $\lnot A \lor \lnot B \lor \lnot C$ and add the following $2$ clauses:  

$\lnot A \lor \lnot B \lor \lnot E$
$\lnot B \lor \lnot C \lor E$ 

You will get a minimal unsatisfiable formula with $n=5$, $m=9$ obeying condition 5.  

In general, you may randomly pick a clause $l_1 \lor l_2 \lor l_3$ and split it in $2$ clauses:  

$l_1 \lor l_2 \lor v$
$l_2 \lor l_3 \lor \lnot v$  

where $v$ is a new variable. Each time you do so, both $n$ and $m$ are incremented by $1$. Repeating this process allows you to "stretch" the initial unsatisfiable core, and to obtain minimal unsatisfiable formulas (obeying condition 5) whose $r=\frac{m}{n}$ tends to $1$ as $n$ grows (which is pretty rare, as formulas with $r=1$ are satisfiable with high probability).