There is a serious issue with this unit: it becomes way too strong when microed well.
1) When properly microed, crabe is almost impossible to catch uncurled, giving him 12 000 effective HP. While thats not really that much hp/cost, its still insanely much for a unit of its range. Most high-hp/cost units are short-range assaults, which need it to actually get close. Crabe, however, has range of a skirm and hp of an assault.
2) Range. When not microed, its 600. When microed its 600+200=800, the 200 being the AOE of its weapon. As result, many units that are often used to counter it suddenly become vulnerable to counterfire if you manually aim the crabe. And these units usually have extreemely low HP because of their role, so even 50% of crabes damage is enough to kill them in 1-2 shots.
As result, you cant kill it in close range due to it having decent DPS and alot of health (and often a line of defence close to it), you cant kill it with skirms because it outranges them, so your only options are precision arty, which usually doesnt have too much of DPS so the crabe often gets healed too fast to kill it. The only remaining option is air, which, while 100% effective against crabe, can be shut down quite easily, and to kill the crabe they need alot of time.
So, personally, id suggest the following changes:
1) normalise his HP. Set HP to 6500, and armormod when curled to 0.66
As result it will go from 4000/12000 to 6500/10000 - less sensitive to micro.
2) Overhaul its attack. Crabe killing some skirms is fine. Having to aim crabe manually to outrange HLTs and snipers is not. Leave the AOE guns to cheap short-ranged units like levelers, where they cant be abused so badly. Not sure what would fit instead, though. Maybe a minimal-AOE multishot, like form behemoth? Or a heatray? Crabe is designed as a riot, so i cant think of many other options.
