(5) the most important difference though is the landing: much flatter than a PA28 and you don't pull back like you do in a PA28 - or if you do, you will balloon/float.
I dont agree.
Having flown both variants and PA28s I think this is a common illusion.
The canopy and the view from the Diamond is very different and leads one to believe the landing is flatter.
In fact the Diamond will land very nicely nose high with the nosewheel kept off the runway until eventually with the stick fully back it has no option but to find the concrete.
I do agree with your other comments.