Hey Burley... welcome to the interweb
Agreed on all points... all knots must be properly cinched and dressed before use... but perhaps particularly the clove. The rig I've been playing with lately when I need adjustable point is:
1) Ballpark estimate the rope I need, then add another arm length or two
2) Fix rope to anchor with 8-on-a-bight
3) Clove onto belay loop of harness
All the adjustability you need + backup of clove hitch + adjustable point always with you in the event you're more than arms length away from anchor (like say for Stairway at Sunnyside). Cost = 1 extra locker.
I dunno... anyone got a better system?
p.s. 100 posts... what do I win?