Welcome to the forum. I'm short on time right now, so I'll address the most important questions.
2. If you want to take it down to the point where the car is warning you and the estimated range disappears, the important thing to remember is to plug it in to recharge immediately afterward. That more or less mitigates the effects of running it too low. Do that anytime it gets below 20-25% charge.
3. Nissan Connect EV. I don't know if you can use it in Malta, though. (Interestingly, I live 10 miles away from Malta, NY, USA.)
4. Yes, an inverter is what you want, preferably pure sine wave. You can pull up to 1800 watts, but I suggest limiting it to 1500. If you want to do that regularly, at home, you might also consider getting a 50-100+AH storage battery, to act as a buffer. You'd connect the car to the storage battery, and the inverter to it, as well. That would offer some protection for the car's little 12 volt battery.'
6. No, I'm afraid not.
8. It's essentially harmless if the battery isn't hot or ice cold. It has a negative effect on longevity if the battery is hot, or very cold.
Brilliant Silver 2021 Leaf SV40 W/ Pro Pilot & Protection
2009 Vectrix VX-1 W/18 Leaf modules, & 2 lithium E-bicycles.
BAFX OBDII Dongle
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.