A comment on the use of a torque wrench, I don't use one except on the rear wheel bolts.
Torque wrenches, especially the beam and pointer design are inaccurate and often make tightening a fastener clumsy and potentially inaccurate.
Develop a feel for the tightening of the various fasteners you routinely install. For example, the oilhead has 8 valve adjustor nuts that must be snugged each time valve lash is disturbed and reset. I never use a torque wrench for this. Develop a feel for the correct amount of torque to apply. Its common sense.
Think about securing a wood screw into soft wood...how much force do you apply to eliminate the chance of stripping out the wood threads? Use the same thought process when securing fasteners onto you bike or car. You are often better off with less torque rather than more. Also, are you threading into ferrour or non-ferrous parent material? It makes a difference. Alloy is buttery and thread damage is likely if you over tighten.
Yes, a torque wrench is needed if you are tightening engine, clutch and wheel fasteners. The rest? I use feel. I have yet to loose a screw or bolt on my 2001 GS and have not lost a thread.