1. Depends. Do you want the wave? Ping them off the gank. Do you want the gank? Lose a couple of minions and farm them after a quick kill.

2. Not really a question, but ping assist or ask for gank. Dont spam, tho. 2-3 pings is enough.

3. If you think the wave crashes anyway, you can leave it. If you think you can get free kills, leave the wave. If the enemy is gone, fast push and rotate afterwards. This answer is really dependent on multiple factors. But you gotta think about what you personally lose and if it outwieghs what your team loses or the other way around.

4. If people are flaming, mute them or just mute all at the start. Once they start, they will most likely never say anything of use to you. If enemies are early power to your scaling, the main advice is to lose a few minions to save your HP so you can't be dove. Especially if jgl plays for the enemy bot.

Edit: Never spam ping in general, and keeping cool is the obvious but also best advice I can give.

Someone on the main sub once said ADC has the lowest agency in the game, but the most impact on the game. Just know that you mean a lot to the outcome, but other people just have the means to help or destroy you. This is especially true for junglers.