I would strongly advise against timed choices altogether. I say this not because it’s impossible (it isn’t), but because it puts a harsh onus on slower readers even when you have a reading time variable. There’s no way to account for different reading styles and conditions that affect reading speed (drunk, high, low mental energy, distracted by environment, frequently interrupted, dyslexic, etc.). I’m a very fast reader, but on days when I have low mental energy, I read at a snail’s pace.
Naming your friends and choosing their gender is 100% possible and a pretty common trope for COG games. You just have to code it using variables. Here’s the method I use for creating gender variables for the player, which can easily translate to NPCs.
I will say that “millions” of words is… honestly not super realistic for your first WIP. You’ll find that the average full-length COG/HG is around 80k-250k with some major outliers, primarily on the upper end, with an average playthrough length of 30k-45k. Honestly, a game with a million words might actually be too big to submit! 
If you’ve got an idea for a game like that, I definitely recommend breaking it up into a few different games so you can give sufficient attention to the details without having to worry about dealing with a buttload of variables, states, and conditional texts.
I’m not super sold on the hardcore mode only because I don’t like difficult games haha. It’s certainly possible, but just know that it will expand your workload significantly to have two difficulty modes. If you’re going to pursue a game that’s the size of what you’ve planned, that will significantly increase your workload and the time it takes to release. I tried something similar for a game, where I had three difficulties that affected how much starting supplies the MC got, and I dropped it quickly because the scope was too large.
My only other suggestion is to limit your scope. I get that it’s super enticing to make a huge, expansive world, and some people are better suited for that than others (case in point, I am decisively not suited for that). However, the best games usually have a tight focus with interesting characters. I’m part of the “characters > plot” camp, but everyone is different and someone is going to like one thing over the other.
Good luck! I hope my advice and the advice of others helped you out!