Suggestion..

I have recently returned to the game after about 3 years and notice a few changes - the top level for a start. I really enjoy the lower levels though, which is why I have had 6 or more different chars in the past. What I think should be tweaked is the Teganswall quests. There are several maps there and I, certainly, whizzed through the quests. Compared to later maps where a tedium of grinding is necessary, I think those maps could be savoured more.
I realise I have experience here, but after 3 years I'm fairly rusty, so I have a feeling that the difficulty level has been lowered - or does it change between servers?

 

Nah, it's gotten easier and the level up has been sped up since it was taking players forever to level up between level 40 and level 45. Especially with the parallel world now accessible for lower level secondary characters to not have to go through the whole line of quests with each character again and again.
I think a very good example of boss that became extremely easy nowadays is Khalys. I remember how impossible she felt to me years ago when I kill her, and how easy she is to deal with solo now.
Events too have gotten pretty easy and grindy too compared to the "old times". Some players complain about this, others enjoy it. I guess it's a matter of "can't please everyone" and adapting to the new times.
Good luck and welcome back!