What on earth?

Is the machine perfectly level? Check it with a spirit level......and, silly as this sounds, are all the transport bolts out?

As for the rubber feet stopping it moving, be prepared to replace them on a regular basis as if the washer continues to 'want to move', they'll wear out fairly quickly.....

If the machine is not level left-front to right-rear and right-front to left-rear, then no amount of left side level or right side level adjustment will fix it. It is the vibration caused by the opposite corners being out of level that will make the machine move.

I'd not call a 2004 machine "vintage"..
Ge OTOH got really bad, for me last acceptable machine they made was the filter-flo, it takes nothing to wash better than a " ta-tack-ta-tack ta-tack" 2004 GE...you barely see load moving in them.
Scratching of the rear tubs is common in pretty much all front loaders I've seen in my life, we talking light micro-scratches , it's rather weird that Speed queen doesn't, however  these scratchings doesn't indicate a poor quality stainless.
I always think a keeper heater may be a good thing in a front loader.
Australia matter: My  own ideas about are that in the US things gone differently than Australia, take good not bad in  what I say..

Average Australian top loaders got "worse" sooner and more commonly than US and more Toys-plastic-like etc cheapy Asian-like etc... that already brought many to go Front loader by themselves  as they cleaned better than the average newish Au top-loader offerings (exceptions  existed of course but that's a general speech),  in the US you had  excellently functional sturdy work-horses till recently and situation  only changed substantially as the government unfortunately wanted so.

Of course as you know I said many times I believe the main concern of the gov was to make/induce folks go He for the obvious economical agenda  and interests/business all these enviroinmental stuff  brought and is about in the US, it was a money driven thing  not actual about the enviroinment but the money, that translates in  "as long as they bought an HE  that's okay, they can even wash one shirt at a time now and we don't care",  so I say a reduced load will likely get them clean, and that's infact what people will do.
Though in Oz  things have been a bit different and  is the actual necessity/will from the folks  that brought many to go to a lower water use machine, machine that as I said often provided better cleaning too than the average top-load offerings over there and front loader was what had been favourite, of course you had no many odd attempts to make weird configurations from the oz manufacturer like in the US, some US imported HE yes, but not from Australia,  not so much boasting of HE, not HE selling strategy and brain-washing at all, then all had also had been facilitated by the fact Australia shared the same voltage and hz as Europe..so it was just a matter of importing  the models and eventually gear up an own production....
I explain better....in AU you didn't have to induce/force to go to a front loader, they just entered the market and nobody said any company  to change anything , as I said many already  found them to clean better than the average australian top loader and of course needs such as droughts made people even  more willing to get a front loader killing all the cons they could possibly still have to someone..hence you have a non-forced market, in the US instead you had to tempt folks and claim all possible wonders  about HE and front loaders as in the US they had no actual necessity to do otherwise, they had machines cleaning wonderful no common drought problems (except some specific areas) and  of course a machine that took more than an hour to do the job was something many people didn't want or were more reluctant to deal with vs their old top loader that worked so well, so what happened, they just made front loaders that completed cycles sooner in order not to make that big difference with the short cycle of a top-loader, this was found being fixable anyway by loading them less...which is not so much enviroinmentalist but again, I fully believe it was  just a money thing over there vs what has been elsewhere.

As long as they bought a HE machine government  was happy..what they had to do after nobody cares...in australia not..they were made and sold to work as a front loader is  supposed to for all load sizes, and a longer cycle is contemplated in the picture.
Maybe also the water hotness or issues about getting enough hot water in australia also played a role in the lenghtening of cycles.
So Qualin was probably sort of right by saying  ozzies  pack more the machines, but that is kind of normal to be so...

A 60 degrees heater is  okay for laundry purposes, this is the minimum folks usually keep theirs over here and  if you want more hotness one can always add a safety mixing valve after the pipe attachement going to the machine/laundry area,  so you have actual proper hot water for laundry and the rest servicing bathrooms and so forth, and priming is of course a due to step for any non-heating machine if you want the hottest wash you can get.

I speak for what I see, as I surf many  AU shops I see an higher number of front loader models vs. the Top loaders, the top loaders are also often asian pulsator now as autoctone manufacturers got bad, so non-agitator machine, in the recent past you had an higher choice of agitator machines and less asian-like washers, this is a change I've seen happening really recently.
Also, I see an always greater commonnes of newish front loader machines as I surf classifieds, ebay and so forth, they're typically EU kind.

About the plastic tubs of US machines, it actually is only GE/Hotpoint that uses plastic tubs in some models not even all of their line had plastic, all the rest were either stainless or enamel, in the past there was also Westinghouse  that used plastic but now is a vanished brand on US market and had not a good rep.,  whirlpool never used a plastic tub, of course talking about whirlpool we talk of the greater  slice of US traditional top load market, so kenmore, roper, estate, Maytag etc; then there are the new HE which are not traditional.
I like enamel, is great, and find it best than many stainless tubs, australian tubs looks so filmsey and are also often welded/assembled with plastic parts, can confirm the same also of many asian-like pulsator machines that are common here too, those machines are toys and not made to last and not even find them good at washing, so quite honestly if I had to chose from a thick US enameled or plastic tub and an Au stainless but filmsey one I'd personally go US tub any day...
Also US machines cost more for 2 reasons, one is that they're built more durable and use better materials, and also are stronger, a model like a Speed Queen will last very very long, second is importing costs, they cost alot here also.
Australia agitator machines had pretty much all from awhile weak motors and lack of gearboxes much earlier than this trend started in the US, back and forth was reached from the motor and you had long slow strokes in many machines,  tubs would also  index or move along in many models, and again the matrerials were  not that  good, they're filmsey machines and even though they spin higher I'd not want to deal with one of these newer ones as I don't even like the agitation, different matter was for some of the older 90s ones that seemed still be sort of acceptable but filmsey and plasticky the same VS Us models, even though in the past they seemed anyway a little thicker, as you go back in time you also had stronger machines....
US machines simply  are more value, but yes they're expensive and not all can..My opinion...

US He top-loader as I said are not popular there and you only have some models, and that also includes Samsung and LG.
F&P offers an HE model that though goes strong abroad not much there, F&P is probably the TOL autoctone (actually IIRC is NZ) maker, not a case Fisher Pyakel models  are sold abroad when ones like say Simpson or Hoover doesn't and never did.