my new questions.
#1.  how long should I expect to run a nozzle before a cleaning on PLA?

I've been cleaning with two drill bits and a torch.  running the bits in by hand to draw out the plastic.
#2   What is your preferred method.

As wardjr said - I don't clean my nozzles either, unless i get a clog on a rare occasion. You really shouldnt need to "clean" the inside unless you are clearing a clog.

New problem.  I'm running the crap out of my machine
Last night the Y-axis started jumping teeth.   I lubed it well with light oil.  But it still seem stiff.  I took the y axis apart and all parts seem to slide smooth independently.  but when I reassembled...it seems a bit stiff as an assembly.  I futzed with the tension and now I wonder if the belts are too tight
#3  how do you gauge belt tension

I run mine tight enough that they can just be pinched together in the middle with the carriage parked at one end...

#4  any ideas of how to loosen up the y-axis
( I know that #4 could be a hundred different answers...give me a couple of top choices please)

is everything squared up? if one side is slightly ahead/behind the other side it will cause it to bind up...
Loosen the set screw in the right rear pulley, and work the carriages back and forth a little, stopping with things in a neutral position and tighten the set screw again.

#5  is light oil (like 3 in 1) the right choice?

I use 3-in-1 oil all the time on the smooth rods. If you dont think that is enough, you can try a very thin coating of white lithium grease (available at most auto parts stores)

I've reduced retraction to 1mm and that has solved my problems.

my new questions.
#1.  how long should I expect to run a nozzle before a cleaning on PLA?

I've been cleaning with two drill bits and a torch.  running the bits in by hand to draw out the plastic.
#2   What is your preferred method.

New problem.  I'm running the crap out of my machine
Last night the Y-axis started jumping teeth.   I lubed it well with light oil.  But it still seem stiff.  I took the y axis apart and all parts seem to slide smooth independently.  but when I reassembled...it seems a bit stiff as an assembly.  I futzed with the tension and now I wonder if the belts are too tight
#3  how do you gauge belt tension
#4  any ideas of how to loosen up the y-axis
( I know that #4 could be a hundred different answers...give me a couple of top choices please)
#5  is light oil (like 3 in 1) the right choice?

A direct drive system shouldn't really need all that much, but a bowden can require a fair bit more.

For most materials my direct drive E3Ds use less than 1mm - some materials do require a little bit more (nylon), but not by very much.
One the other hand, the kossel with a bowden system and an E3D is more like 4-5mm.

different hot ends will have different settings.

I've had several successful runs, but they are always hollow parts which means to me that I might be having a problem with retraction.  The hollow parts have minimal to almost no retraction events.

what sort of number in slic3r should I be using?

PLA seems to be doing better

I see the pot ( I think)

1/4 turn, 1/8 turn?

I'm perplexed