The track actually does look sealed but sun beaten. I can see spray marks and can hear tire squeal so I would say its been sprayed quite heavily.

What you are describing is kick up... not quite the same as caster. C-hubs are inexpensive and if you race, you should have spares as well as a selection (4 and 6 deg) for tuning. The club racer kit comes with 4deg C hubs and these are probably the most universal for most tracks.
According to the documentation I have read, more caster = increased initial turn in or "twitchy" not stable for higher traction surfaces. I have found this to be true in my testing as well.

I believe the club racer kit actually comes with 0 degree caster blocks IIRC.

I've never had my car in such a way that it wanted a tight rear diff to gain steering, I could always add steering with other tuning options. A looser rear diff allows the rear to follow the front instead of trying to rotate "on the nose" and holds better corner speed as a result.

On high bite surfaces , you want a tighter diff(1/8th of a turn or less from full lock) to give you a slight on power rotation, and more corner speed... Too loose a diff causes bad performance...

On grip, you want the back to follow the front so you don't scrub energy. If the car looks lazy but runs good lap times, you're probably doing it right.

You GOT better eyes than ME!!

I don't watch RC races with the sound on, don't like some of the music and some of the announcers are as bad as the music.

Manuals show "0" good call.

My first on road race, 3 diff racers WHO I knew, raced with and respected checked my RC. All three said as you did, LOOSEN the rear diff. Point and shoot doesn't work on road. On any track, now even off road, IF there is a turning problem (push) I look at the rear diff now!!!

The track is sealed and sprayed with VHT. By the second qualifier the traction is unreal. They need a new sprayer......note the streaks.. I may even try some good used tires.....

I checked my diffs..... Plastic for front and rear. 1/2 turn from tight on the front and almost 7/8 for the rear. I adjusted both to just a tad lower then a half a turn. I plan on running a solid axle in the near future.....

Way too much torque for plastic front diffs at these settings: no wonder you were getting rear ended.... Your diffs were slipping, and you'll see a big difference with a front spool(and will's DCJ mod), but I would tighten the rear diff to at least a 1/4 turn from full lock.....

Knowing that you have a ball diff in the front explains a lot. Your car will immediately drive easier once you lock down the front drive. As mentioned before, there is a mod you can do if you don't have the spool yet. Remove the diff balls and either compensate fitment with shims or cut some cardboard stock discs to act as friction plates/spacers on each side of the diff half and tighten it down.
I notice that you are hitting the brakes at the end of the straight too. Are you concerned about traction rolling or still building confidence in taking a fast corner? A lot of crashing there so it's probably intimidating to carry as much speed as the car can handle. Either way, once the car feels easier to drive, your confidence in it will improve as it becomes more predictable.
VHT is very good stuff and you probably don't need much saucing. Perhaps try applying your sauce at the beginning of the race prior to yours and wiping it off half way through as you head to the track for your heat. The duration also is dependent on track temp and how heavy the spray is. Since you are in sunny Florida, 36's are probably the most consistent tire for your track.

Actually my car feels more stable (especially on corner entry) with the tighter rear diff. It did decrease the turning radius a little bit as well but mostly it settled the car down. At this stage the car just feels better and is faster for me with a slightly tighter setting, period. I am not talking crazy tight, something that feels like maybe 10000 in a modern TC. I just have a hard time having a smooth diff for a long time with this setting.

Another question for you: what front-back weight bias would you recommend ? I saw you mention a heavier front in another thread, and apparently the pros do indeed run a heavier front on their TCs, at least on carpet.

Will's DCJ mod? Not a BERT mod?

It is worth saying that depending on your type of surface, grip level, suspension settings, whether or not you run a front spool, and things like that tightening your rear diff can cause either more or less rear grip. It's hard to predict, but easy to test.

I just seem to have a gift because every car I own, either touring, 1/12, or offroad, never has any problem generating front grip. Maybe I use too much sauce on the front but it's the way I found that I could make the car more consistent run-to-run and during the run.

As for weight distribution, most new touring cars built the way the instructions say to build it are a bit lighter in the front than the rear. I like a little more front bias, 50:50 or somewhat heavier in the front, as the increased forward bias takes away a little of the tendency to over-rotate on corner entry and makes the car easier to drive, smoothing out the transition between high-speed push and mid corner. It also gives a little more on-power steering and control because it keeps more weight on the front under power. The general rule of thumb is that increasing your cars rear-bias will give more turn-in, and lose grip on corner exit. There are exceptions to every rule, of course, so your results may vary.