Ooh, here's a dumb suggestion: "Freeze!". Pace of the game too fast for you? In this variant on existing modes, every four seconds, the game starts or stops - that is, four seconds of action, four seconds of nothing but camera movement (but not weapon aiming - camera snaps back to where it was after that time is up) and thinking time (ink doesn't recharge, you'll even stop if you're falling through the air). The 'action' portion of the battle still lasts as long as usual, so a Freeze! Turf War would be 6 minutes in total, etc..
Something for Aerosprays and Inkbrushes to shine: "Mirror Match" - again, a ruleset variant on standard modes. All maps are perfectly symmetrical, so each point on your side can correspond to that same point from the enemy team's perspective. In this mode, inking a point also inks its corresponding opposite point, making turf control (and Ink Resistance) more crucial than ever, as you can slow down and damage the enemy team from the other side of the map, right from the start of the battle!