I think Sweden are really excellent actually, and better on deity. The reason being that when you are at war you get 3 sources of great people: Generals, Admirals, and the prophets that you can steal from AIs!! All three of these great people tend to be much more common on deity, because there are more units to go and kill, and the prophet spam needs no introduction.
If you are lucky enough to get a religion then you get another source of prophets. With Sweden you can use them to spread religion 3 times and then gift to city states.
If you like peaceful play, you might give Morocco another go. The trick is having several different AIs within trade route range. The extra gold is quite substantial. It might have you using more external routes, but since the AI get extra gold for each trade route sent to Morocco, even playing as normal you will notice the extra money. Very nice for every VC!
I actually find Morocco really underwhelming. I notice they are highly ranked on the tier list cited earlier in the thread, but I find their UA very situational really. As you say, you need multiple AIs nearby. Also, I don't really buy the argument that Morocco's UA makes the AI more friendly. In my experience the AI needs no encouragement to send trade routes, and they seem equally likely to cancel and declare war when playing as Morocco.
Portugal is better in my opinion because it works equally well with city states and single neighbours. It also comes with a coastal start bias, which is useful for trade, and probably ends up with a higher base gold bonus than morocco, obviously depending on resources.
To throw another civilization in the ring: Assyria. I seldom see Assyria highly ranked, but it's UA can garner about 15-20 technologies in a game! As long as you plan a little (e.g. pick up 2-turn optics before capturing a city) you can avoid it being wasted on poor technologies. I find when stacked with Autocracy spy stealing, this UA can really let you bomb down the lower half of the tech tree late game without worrying about falling behind too much. Siege towers are situational, but certainly not useless...