Mind you I speed for any BNW difficulty up to king, as that's what I played.
Rome is really versatile, but their UA seems to have far greater effect at wider gameplay.
Conquering your neighbours with the Legion, option to build a road with Legions to your if its rough terrain or your units will travel slow, if your gold can afford it, conquer a good city and you have a connection
Balistas in their peak time are really good, 2 more base damage means 2+200% =6 more strength vs cities, more with an early general from the honor tree.
If not going early warmonger, Tradition has benefits for going more expansionist early, faster worker speed, city connection bonus, building construction bonus.
I think the most UA benefit comes out from high production on regular buildings, the UA can speed up the other cities quite a bit (25%).
Seems to be fairly good for getting national wonders, but you gotta watch the build orders

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I think Domination/Cultural/Diplomatic victories are all possible, Science as well but heavily dependant on the map (mountains = observatory, growth vs production)
If its like a larger map size, early warmongering seems less beneficial with more civs as you'll obsolete the units. Unless it's like a small contintents map with close neighbours or a big resource gain.