Does a torque anchor prevent an IGH (Rohloff Speedhub 14) from being pulled forwards and crooked whilst riding? Assume a bicycle with horizontal fork ends (like the rear facing horizontal fork ends on a Surly Troll), with an IGH (Rohloff Speedhub 14) and no chain tensioner. On a steep uphill in the easiest gear, the rear wheel might be pulled forwards and crooked. Does a torque anchor prevent this? Or is a torque anchor used to solve a different problem? (I'm refering to this answer (< to my question about Surly + Rohloff which mentions a torque anchor.)

No. The torque anchor is on the non drive side and only serves to counteract rotation of the inner part of the hub. Use Tugnuts or equivalent if you think the wheel might be misaligned due to pedaling force.