Your expectation of how long these tasks will take is way off the mark. One cannot accomplish very much at all , of any quality, in 1 to 2 hours.
Fixing ‘niggles’ is rather quite nebulous in description and could take any number of hours depending on the severity of the ‘niggle’.
Rigging a very simple armature could be done in 1 or 2 hours, but could take days depending on complexity of the creature being rigged. Especially so if the creature has any ‘niggles’ that need to be corrected before the mesh meets deform expectations.
A walk cycle, again dependent on creature complexity, could take more than a few hours.
I should think that 1 to 2 hours would be time required just scrutinizing the project at the various stages of development. 15 minutes here… 10 there… Does is look right? Is it deforming correctly? What needs adjusting…