Every time I've done a zero balance and used the marks on an arm, it's been pretty far off (usually by more than a decigram). Whether this is from not finding the true zero point, inaccurate markings or a combination I'm not really sure. Scales are so cheap now (<$20) that it's really hard to justify not having one.
Antiskate should be set by what the arm/cart needs. The numbers don't mean very much. Personally I consider the blank LP side method of setting AS to result in too high a setting. I prefer to use the tracks on the HFNRR test record for this purpose, but doing the blank side and backing off a bit is usually good enough for government work.
According to CartridgeDB, the tracking force for an Evo3 is 1.7-2.1g. It is always worth remembering that tracking too light is more damaging to records than tracking too heavy. Also since it's an elliptical, fine tuning VTA would be very helpful, although your up the creek there having a Rega.
