I use the Bane build as more of a WM-using stalker with several ranged attacks in order to fill out my attack chain. Here are the ranged attacks for the Bane:
Mace Beam
70 ft range (standard) and a quick recharge. It does half smashing and half energy and, both together, does about 75% of the damage of the half smashing, half toxic bash. This, with the fact (imo) that toxic is less resisted in PvE than energy, makes Bash a better choice.
Mace Beam Blast
I use this power in my bane build. It's a targetted AoE and does half smashing and half energy. Its damage is half that of Mace Beam, so consider it to be a weaker AoE version of Bash. Not very useful against single targets, but it's a nice addition when you build for crowds. Note that it does KB, so use it with caution.
Mace Beam Volley
45 degree cone, about 75% of the cone for Suppression on the crab side. It's 75% energy, 25% smashing and does KB. It has a recharge of double that of Mace Blast, which is about the same as any normal corrupter heavy ST blast. Except that it's cone. Except that the cone is somewhat large. Per target, it hits for about the same as Mace Beam Volley, so about 60% of the damage of the ST Mace Beam.
Poisonous Ray
This can be a beautiful power. It does the same damage (roughly) as Pulverize but does it all in toxic damage. Its recharge is a second slower than Mace Beam Volley, making it a second longer than twice Mace Beam. It's single target and imo it ought to do a little more than 7.5% def debuff since it's a "poisoning" power, but what are you going to do?
TL;DR
There are more ranged attacks available to Banes than there are melee attacks available to Crabs and the ranged attacks on Banes are more viable in an attack chain. On the upside, the single target powers do similar damage to the melee powers from a short distance away. On the downside, the AoE powers have to have two or three targets minimum to make up for the drop in damage potential.
Another minus is playstyle. As a bane, you're sneaking in under stealth to smack some fool upside the head with your big [censored] mace. However, noting that your pivotal powers of Crowd Control and Shatter do KB (which can then be followed up with an AoE if you position it correctly), you can form a solid attack chain that flows well imo.