Rule #1: All suggestions are fun only in the eyes of their beholders. Only you know what's fun.
On to some basic advice from a newbie to a newbie:
Central Staircase (or two). Maximize use of vertical space to minimize travel distance, reorganize accordingly - vertical space allows buildings to reside short vertical distances away from many other buildings, rather than long ones on the same z-plane. Sprawling within one level maximizes travel time, and reduces efficiency - you've already noted you're not set up to use Z-levels yet, but think about moving that way for the future! (As a side benefit, you might hit other levels where the ground is more amenable to miners with lower skills than the granite!)
Internal Security. Simple traps in main arteries, designed to soften opponents who get past your defense, are not as effective as a an impenetrably secure perimeter with specialist workers, but if you make a miscalculation, they can save dwarves while the militia assembles. Think about how traffic flows in your fort and how it could be restricted to prevent invaders from having the run of the fort while civilians nearby are scrambling away in panic.
External Security. You want a perimeter defense - something that stops people from simply getting into (ideally: even seeing) your fort. Civillian dwarves do not generally fight well, either dying or suffering from industry disruption if even looked at by a hoary marmot. You're removing those ramps, but does your internal water supply have something to keep the riff-raff from coming out of the water supply? How will you handle attackers who fly over curtain walls, like eagles?
Stone stockpiles are generally bad to implement, in my opinion - they create lots of hauling jobs over long distances, because stone can't be binned in the raw and so can't be stored in small spaces. (It would be better if they could be binned to large amounts - perhaps by being added to internal storage of a new trade depot-size construction for the purpose, but that's also not quite as strictly 'realistic'.) I also dislike clutter, but it's inevitable in Dwarf Fortress unless you learn to apply magma everywhere. You can, however, minimize the stones-everywhere-you-look issue. Instead of stockpiling, create a temporary, 1-square garbage dump zone - perhaps near a central staircase. Use d-b-d the stone to dump it in the garbage pile, then remove the zone and reclaim all of the stone - it will sit in one pile and wait for your masons and crafters, and takes up only one space, which looks neater to the eye than the massive stonepile. (It does still use a lot of labor - all dwarves who aren't set to not do so will come running to dump the stone in between other tasks.) Be wary of what you dump, however, as this will get dumped in the closest spot (possibly your stone pile) then rot when you're not looking and create miasma to make dwarves unhappy! (You can avoid this by digging down a few levels, and then pre-clearing them of stone one level at a time as you go.)
I can't make it out in the screenshot, but you didn't mention a farm, and you appear to have no booze. This is bad for morale, slows dwarves, and creates bad mojo. (
http://df.magmawiki.com/index.php/Booze) You can counter this by sending dwarves to pick berries (d-p) if you have them on your map. The berries can be brewed while you start formulating a plan to farm. You'll need to irrigate the farm (wash it with water that evaporates off and leaves mud) and plant subterranean crops or start to farm aboveground crops to produce things to eat - or at least brew. I recommend the wiki article on irrigation (
http://df.magmawiki.com/index.php/Irrigation), because plump helmets are awesome and can be eaten and brewed to produce more seeds and build up a stock of those...