Been using nylock nuts on most bolts on the kit but which bolts should i be using (bottled) threadlock? ie drive shaft bolts etc?

it wont do any harm but its a bit overkill just use a torque bar, i do know a kawasaki guy who usese threadlock on evrything.

As yours is a BEC use some on the Propshaft Adapter and related Nuts and Bolts. Propshaft to diff. Diff to drive shafts.

Just one thing to be wary of - the bolts which secure the prop to the adapter - chech these regularly as the bolts themselves are used as a means of driving the prop. They have a tendancy to stretch/deform a little and may work lose.

Steve