1. Time travel. I can travel using my current body (to see the distant past or future; can also bring people/things with me), or travel to a point in my life into the body I had then (e.g. to relive my childhood). Altering history causes the timeline to split to avoid paradoxes, and I can travel between timelines. I'll always know which timeline is the "real", unaltered one so I can use it as a reference of sorts.
2. FPS-style console. The console always understands what I type into it; no "unknown command" errors. Time stops with the console out, so I can use it to think. I can use it to toggle cheats (Haruhimode, noclip, invisible, etc), alter the properties of objects, and spawn things. As per the rules, I can't spawn living things, but I'll still find a way to be with my waifu.
3. I guess I'll do like >>10690 did and wish for the genie's freedom, just as thanks.
There's so much to do now. So many scenarios to study, ranging from what my life would be like if I took different classes in school to what the world would be like if we never discovered oil. And if I don't like how something turns out, I can just come right back home and think up another scenario.