Your attitude about spending is confusing me. You say you want to know how much to cut every spending category to be FI in 15 years. Well, why do you want to be FI? What do you value? I think you will be more successful with cutting spending if you start by re-framing your goals and needs. The beauty with spending consciously is you realize that you don't need to spend a lot to be happy. And it's a gradual process - you start by eliminating some wasteful habit, then you realize life is still good and you don't feel any worse, then you feel more comfortable applying that to other areas, questioning, not doing something just because others do, and not caring.
Congrats on upping your 401k to 10%!! My suggestion: start tracking all your expenses. Sign up on mint.com (or personal capital) and go through every evening, or once or twice a week, and move all of your expenses into a spreadsheet, breaking spending out by categories. This will be eye-opening and you'll see how much you actually spend on everything.
Rent: 1010
You said above that you have a 2 bedroom!! That's totally crazy for 1 person, why not get a roommate?
Internet (mandatory for work purposes): 50
Can you get this lower? What about using
http://www.chicagocheapinternet.com/ to find a cheaper option, then calling your provider to cancel and switch, and getting a lower rate from them as they do what they need to to keep you as a customer?
Utility: Gas 60
Utility: Electric: 80
What can you do about your utilities? Can you call your provider and have them do an energy audit? My husband and I pay about $20 for electricity. Do you make sure to turn off lights in rooms you're not using? To you keep appliances unplugged? Can you talk to your neighbors and see how your bills compare? Can you put up insulation for your windows?
Cell: 50
Switch to an MVNO (look it up on wikipedia - I have a Verizon MVNO called Page Plus Cellular, my phone (iphone 4s) costs $33 every month, and there's no contract. You can do even better depending on your needs. How much data do you need since you have wifi at home and work? Why not try disabling data on your phone to curtail random facebooking etc and see how much data you don't need?
Train (mandatory): 185.25
Food (including restaurants): 400
You can do so much better. If you're not a confident cook, talk to your friends who like cooking and ask for some of their easy or in-a-time-crunch recipes. Are you happy to eat the same thing for dinner multiple times if it's food you like? Try bulk-cooking so you have several meals (like
http://www.budgetbytes.com/2013/05/italian-wonderpot/), and keep snacks handy for times you're hangry (granola bars, hard-boiled eggs, veggies + hummus, etc).
Student loans (mandatory): 300
Travel: 300
Are you doing the bare-minimum work like getting credit cards with bonuses? Check out Barclay Arrival Plus and Chase Sapphire Preferred- they have promotions like spending 3k in 4 months and getting 50K points. If you spend that anyway, it's an easy way to save tons of money on flights.
Gifts: 100
Who are you buying for? That's a lot of money - are you doing this because you love to, or because it's a habit you never questioned? Talk to friends/family you gift for, see if they might not prefer something experiential (that can be inexpensive) like getting gourmet coffee then going for a walk, or coming over to your place for some wine and conversation.
Lady stuff (hair, nails, brows): 100
Hmm. Plugging your own eyebrows is really easy (and I actually have come to really enjoy it). Buy some nice tweezers and a magnifying mirror, and you're good basically forever.
Uber rides/cta transit rides: 150
Going out (play/concert/museum/movie/bar/dance class/etc.): 100
I'm sure the default among your friends might be going out for dinner or for drinks, so be proactive about the inexpensive things you can do - people will probably be amenable to a change in plans as long as it doesn't require effort of them. There are lots of things in Chicago -
http://www.timeout.com/chicago/kids/activities/free-museum-days. Also, consider hosting your friends at your apt - a box of wine and some baked potatoes and garlic sour cream sauce (or cheese and crackers) are all you need if you've got the awesome people. This will be a lot cheaper than going out, especially if other friends take turns hosting.
Gym: 50
Do you actually go? Check out some groupons for short-term memberships, or where you pay $X for Y visits. Figure out what kind of exercise you can do at home - I personally do crunches and have a pair of 8lb dumbbells. I'm sadly really inactive in the winter when it's cold, but come fall/spring/summer, I'm all about running outside, which is totally free and doesn't require any gym membership.
Clothes: 102.03
I too love clothes and looking good. But you need to cut this out - eating well and exercising and being fit is what will make you look good, not clothes. Spend an evening going through your closet (fun music and glass of wine go well with this), go through all your clothes and figure out what you don't wear/don't like/feels uncomfortable, and donate all that. With the rest of the clothes, try on different outfits and combinations, and remember how many awesome things you have to wear. Unsubscribe from all the store emails - they'll just make you want to shop. And stop using shopping as a recreational activity - stay out of stores and you'll shop less. Some of this will depend on your personality - I am totally fine not shopping, but of course whenever I do go into a store I have all sorts of desires to buy cute dresses, etc, again. So I pretty much don't shop, buy necessities from Amazon, and when I look at stuff for fun (like a new hiking backpack), I put it on my wishlist and don't buy. The key is if I really want something or need something, I get it, I don't deny myself. I just spend consciously and generally that means when I'm thoughtful I buy less.
Good luck!