Thanks for the write-up Oracle, this will help people who have never done this before.
Wanted to mention that the above description does not apply to me. I have used the golem training method for years to train wrestling, swords, fencing, and archery (never built a macer) on several dozen characters across most of the shards at one point or another. I'm a bit of an obsessive character builder, it's a curse. The issue I'm now experiencing is new, I have never had this issue and I'm wondering if other people are experiencing it or is it a fluke.
Basically I am unable to keep the golem following me while stopping it from damaging me. No matter how many "All Stop" and "All Guard Me" messages I spam nor in what order I spam them I keep getting killed. Vicvega mentioned that this is due to a recent patch/change. I have heard nothing else to substantiate this thus I'm wondering if other's have heard anything about this.
The one difference with my current situation is that the golem was transfered to me from a guildmate in a faction guild. I 120'd wrestling on it and passed it along to my non-guilded, non-faction character. I created a temporary guild on this character and tried to start training. The above was my result.
Feedback on your write-up:
5.Join a guild if you are not in one already. You can also start your own which is not very costly.
This is applicable when training in Trammel, if in Fel it is not required.
5.Use the Context Menu on the golem and select the "kill/attack" option and target yourself, then QUICKLY press your enter button.
This is where things started to get a little odd for me this last time and the reason I brought it up in the shoutbox. When selecting Kill from the context menu and targeting myself I got a message I've never seen before that was something along the lines of "...doesn't think it should attack that..." or something similar, I'm at work so I can't check. I could only get it to attack me by attacking it first. Also, you need to make sure you type "All Guard Me" before hitting the Enter button in this step

Couple other points:
1) It is no longer possible to do 0 damage to the golem with a 100% poison weapon. It was quite a while ago that this was nerfed. Now there is a minimal amount of damage done no matter what your weapon is. This means that you have to regularly repair both your golem and your weapon (unless the weapon has good Self Repair). I've done this with a tinker standing there repairing the golem every now and then from a second account. Also, Gift of Renewal used to work to heal a golem, not sure if it still does though.
2) When training Wrestling be sure to wield a fishing pole. This will allow you to swing at max speed and not damage the golem at all. I have no issues with the golem attacking me with this method because I am not damaging it.
3) You cannot train in a guardzone however you can train in a house.
4) The best golem has GM wrestling however this is not a requirement, it just means it's better. I like your suggestion of keeping within 20 points of the wrestling skill, I've followed this rule in the past by simply getting myself to 80 to start golem training however 70 works ok as well. I've never thought to be as precise as +/-20, that's a good suggestion.
5) "Pre-patch" golem's are golems that are still in rotation after the patch that nerf'd the "no damage with 100% poison weapon". These golem's can still be trained on without being damaged or damaging your weapon. They are also expensive if you can still find them, I have one on Atlantic and one on Legends

Hope this helps or at least adds to the thread!
XII