You messed up a few things. Greater Bane does not give the +4 to hit bonus to damage, Seeker is multiplied by the multiplier(and is +8 on Deathnips).
http://www.afterlifeguild.org/Thott/ddo/analyze.php?1label=Deathnips&1bab=16&1atktype=1h&1 spm=90&1phd=1d6%2B5&1phed=0&1phth=5&1phthreat=15-19%2Fx4&1phxcrit=3d6%2B32&1ohd=1d6%2B5&1ohed=0&1oh th=5&1ohthreat=15-19%2Fx4&1ohxcrit=3d6%2B32&1str=40&1dex=10&12wpn=on &1imp2wpn=on&1gtr2wpn=on&1pwr=on&1sneakpct=0&1snea kd=1d6&1cleavepct=0&2label=Dwarven+Axes&2bab=16&2a tktype=1h&2spm=90&2phd=1d10+%2B+4&2phed=3d6&2phth= 8&2phthreat=17-19%2Fx3&2phxcrit=0&2phfocus=on&2phspec=on&2ohd=1d1 0+%2B+4&2ohed=3d6&2ohth=8&2ohthreat=17-19%2Fx3&2ohxcrit=0&2ohfocus=on&2ohspec=on&2str=40& 2dex=10&22wpn=on&2imp2wpn=on&2gtr2wpn=on&2pwr=on&2 sneakpct=0&2sneakd=1d6&2cleavepct=0&report=on&mina c=10&maxac=50
edit: It's important to note that there are reports of extremely high ac(60) mobs in elite mod 6 content. In that range, Dwarven axes are better, unless you're getting a +11 to hit or higher from outside buffs.
edit2: Here's a comparison with the dwarven axes using a +6 seeker item(sup bloodstone)http://www.afterlifeguild.org/Thott/...ac=10&maxac=50