I run an oil cooler on one of my cb750s. I also run in one of the worst cities for traffic and am sometimes in stop and go. Totally worth it for me. It does slow down warm up time though - I am usually half way to work by the time the engine comes up to operating temp.
as for the shindy tach? don't know but I don't trust digital display tachs. Looks cook but I just read dials better.
I run about .002" on the piston...so nothing really special there. The cam has plain bearings and HUGE valve springs, so it can use all the help it can get. It's a bit of over kill, but on fast tracks like Mosport I was toasting synthetic oil...things were holding up but getting very very hot. Switched to an ester based synthetic (Redline), added the cooler...no problems. It's main job is cooling the cylinder head...did lots of mods to the oil system to increase flow to the head. Cooler is situated between the pump outlet and the feed to the crank and heads. Dropped head temps 30-50 degrees post race. Does require a bit more warm up prior to a race. I noticed once or twice that performance on the track seemed need about three laps to come up to where it should be. A warm up lap at about 90% helps.
But yeah...probably needs some of it taped off on days below 70 degrees. Last year a guy asked if it worked when I came in after a race... I said...I dunno...see if it's hot....he burned himself, I still feel bad about it.
PS. To sum it up...yes it was put there to keep oil to the cam, rockers and cam bearings cool. The engine has valve springs from a modern 650 in it and is setup with a 13,000 rpm ceiling (12,000 rpm redline) I asked the head tuner to give me some rpm overhead.