The point of things like DRY is that, if you don't do them, they can slow you down in the long term. You can forget all that and be really fast in the short term. And, if you're just focused on surviving the next six months, that can be what you need to do. But the six months after that may be slower, as the messes you made in the first six months start to have an effect.

Choosing a language for the ecosystem: You should choose languages for their all-things-considered fit for what you're trying to do. Ecosystem is part of it. The programmers you can get (or do you have to train?) are part of it. Another part is, what things make it difficult to write the program that you're trying to write? Memory management? Multithreading? Networking? Certain languages may do certain parts of that for you, and that part of the difficulty just... goes away. Pick the language that, all things considered, makes it easiest to write the program that you need to write.