take a couple days out to write something interesting for the sake of sharing it, definitely. but in the long run, not programming in your spare time is fine. no one wishes they had spent more time programming on their death bed. go out, travel, fall in love, do stuff, etc etc
some people will tell you no, but if you live in brooklyn, possibly with roommates, you definitely can.
i make around that, live by myself in brooklyn, go out and do stuff (maybe not super extravagant stuff) once or twice on the weekends, put 10% of my salary to my 401k, and put roughly $1k into my savings account every month. it works for me.
(also you will need to make your own food every day or buy the cheapest fast food like i do. i am not a picky eater and i do go out to restaurants time to time, but realistically most of your income will be spent on rent and food, so don't get take out every night)
you won't gain muscle doing crunches and pushups. your two best options are either joining a gym and doing a proper routine, or find ways to add weight to bodyweight exercises. creatine won't do much for you. make sure to eat a lot of calories and get your protein.
