You're making things too difficult. You are looking for the one right answer. No such thing. Whichever you pick will have its short comings. Remember programm

You're making things too difficult. You are looking for the one right answer. No such thing. Whichever you pick will have its short comings. Remember programming languages are tools, they exist because they fill a need. Also you have a lot of points here. Get started with one, then move on to the others. You said you are interested in functional. Pick one. The easy way is to pick the most popular. Do a google search. Pick the most popular one, at least you'll be able to ask for help and have someone that's been in a similar situation. For mobile, what do you have available? Pick that platform. iOS takes a bit more money. If you have both pick the one you use the most. I hear iOS brings in the most money but unless you have a great idea it's hard to standout from the millions of apps. For web, look at what's popular so you'll have help when needed. People will tell you to use this or that but once you get started and have a few projects you'll understand what's best for you. You can ask and ask but you will never know until you get going. Define a project, pick what language you find interesting at random and focus on only that until you finish a project. You'll find out what you like and dislike and you'll be able to pick what language is best for you.