Is my anti-skating too strong.

@dover , and there you have it dover. Horizontal effective mass is 25-35 gm and vertical is 7 gm. A normal pivoted arm might be 12 gm vertical and 13 gm horizontal. 20 gms is much to wide a divergence. Your use of terminology is a bit odd. I am looking at a picture of the ET2 as I type. The counterweight is very much a portion of the arm's effective mass. ANYTHING that moves with the arm is part of it's effective mass. In no way shape or form is the counterweight "decoupled" in this manner. 
Over the years many companies have tried to pull this one off thinking that somehow they could get around the laws of physics the last being Frank Kuzma. It should be no great surprise that people resoundingly like his brilliant 4 Point arms better. The fact is it can not be done, at least not that way. They are all destined to failure just like the ET 2. Straight trackers with a motorized carriage carrying a more typical pivoted arm might be able to do it if it were not for the difficulty in overcoming the noise and vibration of such a drive. Reed and Schroder have it right. 
Ditch the ET 2 or use it as an antenna or coat rack or something and get yourself a Schroder LT. You will be much happier and people will think you are a clever guy. It is good that you realize a cartridge has to be chosen to work correctly in a tonearm, that they have to be matched. There is no match for tonearms like the ET 2, none. There are only compromises., compromises you do not have to make with other arms.
Tracking error is not near as much of a problem as it is made out to be not that minimizing it is not a good thing. But, the price you pay with air bearing arms is just too high. 

Just to point out that there is a good argument to be made in favor of a high horizontal effective mass for producing accurate base response. I am not coming down either way on this subject, but certainly there is a school of thought that is contrary to mijostyn’s  ideology.

An effective mass of 25 gms is very high.  Whether or not this translates to a real problem is another matter.  As lewn notes, some arms deliberately have a higher horizontal mass to improve bass response, but, it is usually not that high.  Bass notes are often cut monophonically because cutting bass stereophonically would mean excessive changes in the depth of the groove.  A high effective horizontal mass means that the arm will not swing side to side from the needle tracking the wide modulation of the groove (the full groove swing will be translated to movement of the cantilever instead of some of the movement lost to the movement of the arm).

A high effective horizontal mass means that the arm will not swing side to side from the needle tracking the wide modulation of the groove (the full groove swing will be translated to movement of the cantilever instead of some of the movement lost to the movement of the arm).

Perhaps you could explain why it is imperative to have the cartrdge swinging around whilst trying to measure the groove. Have you ever tried to accurately measure the height of your ceiling whilst jumping up and down on a trampoline - you can't. 

It is NOT ideal to have the cartridge moving.  You want the cartridge position to not change so that the full motion of the needle swinging side to side is transferred to the generating element of the cartridge.  If the cartridge moves, the amplitude of the signal reaching the generating element is reduced.  That is why high effective mass (high inertial mass) reduces the tendency of the cartridge to move in response to large bass modulations.  

Moerch  makes an "anisotropic" tonearm with large outboard counterweights located at the vertical pivot.  Because of this location, the weights contribute little to vertical mass, but, they increase horizontal mass for the purpose of improving bass response.  I've heard this arm and it does have a bigger bottom end than typical arms.  I also thought the bottom end of air bearing arms seem particularly full, but, I have no way of attributing this to the high mass.

I personally agree with you that excessive horizontal mass is quite undesirable.  This probably puts a strain on the cantilever/suspension of the cartridge and might even cause uneven stylus and groove wear.  I have never heard the Shroeder LT or the Reed T-5 arm, but, I really do like the engineering concept behind those arms.  They seem to be the best way to maintain proper azimuth without causing other problems.