Ok last draft, including dragonchild's compressions and optimizations and correcting the case 6 problem which actually saves 3 more bytes.

map{s/X/10/;s#/#10-$p#e;$p=$_}@c=@_;$t=$f=$h=0;while(@_){$s=shift@c;$_
+=shift;/[X\/]/&&($t+=$s+$c[0]+(/X/?$c[1]:0),$h=0,++$f>9?last:next);$h
+=$h?($f++,0):1;$t+=$s}$t
[download]

163 bytes which is basically 1/2 of the previous length.

Thanks again dragonchild.