Couldn't you just reverse the connections? That would give you the desired outcome

Post a pic of the element flange. Sometimes the higher wattage element have two or three legs which are bridged. To de-tune this type of element it's a simple matter of removing the bridge and making one of the legs inactive. I've done this to an Elektra MaxiModern 3grp which was pulling 23 amps and...

All you need to do is increase the temperature of the brew boiler. This is done by accessing the temp adjustment function on the display. Check the user manual if you don't know how to do it

That steam arm lever has been done before. {image}

I've seen a pump head (not motor) get hot once before, but it was on a Gaggia. The reason was because the non-return valve was leaking water backwards towards the pump. This resulted in hot boiler water heating up the hoses and pump. I overhauled the valve and that fixed the problem. On the Linea, t...

How much water do you have in the steam boiler? If it is low and you have a faulty fill solenoid, your machine will be trying to fill the boiler endlessly. This could cause the pump to overheat

The elements are generic. Make sure that the length and bolt pattern match up. If it is too long it won't fit inside the boiler. The beauty of sourcing a generic item is that you then have a choice of wattage, either you can pimp it up so that it heats up faster or de-tune it

Your bad tasting shots are probably due to under dosing. At 15g in a double basket, the shot would be going blonde super quick at which point you are extracting the bitter components of the coffee. Try upping the dose (in the appropriate basket) and see how you go

If you could post some pictures of the insides of the machine, I'm sure someone can point out what component you need to adjust. Just using words is a bit tedious, pictures are a lot more useful. Besides how do we know if it has a pressure stat, pid (for temperature) or some other mechanism controll...

Keep at it with the citric acid, and pretty soon you'll have nothing left of the aluminium boiler! Aluminium and acid are a big NO NO!!