NA player here, so far the game seems fairly populated. I'm having trouble finding a 16x16 plot to put down the cottage plan that I bought, which when I was still playing ArcheAge live post-server merge I had no trouble at all finding somewhere to put something down. I think that speaks quite well for this server's activity. Like trapwhre02 noted though, the game is definitely past its prime so you should definitely set your player activity expectations to where most MMORPGs settle after a few years.
I'm also with you there on Trino's greed. The prices they charged for simple, small things on the marketplace was ridiculous. First thing you'll notice is that this server's marketplace is very reasonable in its pricing scheme. Every dollar will go much further here and evidently they've paid a lot of attention to adding little quality of life stuff like bigger bundles of items like tax certs and making multiple sizes of credit purchasable as items that can in sold in the AH.
In terms of activity and player experience, I think you'll enjoy yourself. Also with ArcheAge live soon to be run by Gamigo, now is a great time to be jumping into ArcheRage if you're looking to experience the same gameplay again.