Thanks for posting this, @Christa-J! I find this topic super interesting.
This is not directly in response to your questions, but I want to share something relevant that I have just learnt…
I’ve started learning Basque and recently I was reading a paper about Spanish-Basque bilinguals (language nerd! ). There was an interesting section about how the brain activates all the languages it knows when it has to use language. This is helpful when it comes to language learning, because as you said above, making connections between vocabulary that sound similar in different languages can help us to remember them!
However, one paradoxical finding from studies on this topic is that highly proficient bilinguals (people who speak confidently and fluently in two languages) find it harder to switch between languages than low proficient bilinguals (people who are learning a non-native learning language and have skills that are significantly lower than their native language).
Sounds a little surprising, right? You’d think that if you know both languages well it would be easier to switch between them. But, in order to not choose words from the wrong language when we are speaking, we need to inhibit the other language that is also active in our mind. In other words, the better we know a language, the harder we have to work to “ignore” it in our brains when we are trying to speak a different language.
If you want to read more about this you can find the full paper here.