We're having a round table just like our guests too! Long tables are boring, you can't talk to all your favourite people at once like you can on a round table.
I don't think you should seperate yourself from the guests with the dance floor. Is the dance floor in a non-movable spot? We're trying to spread guests around two sides of ours. I've been to a tonne of weddings and the best ones for me have a dance floor that isn't 'on show'. People get nervous if they think everyone is staring at them while they dance.
But back to where your table is, we're putting our round one in the middle next to the dance floor. Easy to get up and make speeches, do first dance, cut cake etc, but are immediately surrounded on the other 3 sides by guest tables with the others beyond them. I can post a plan tomorrow if it helps (I nerdily drew my venue up in CAD on the computer