I like OPs enthusiasm and optimism.
Of course at very best you'll get a thank you for your feedback and not much else.
Also point 3 is an airport + immigration (I assume) not AI issue. So you should direct that complaint to them.
Point 2 isn't going to change till AIs financial situation changes a bit. And then they can look at improving that. My suggestion would be for you to visit the SQ/LH lounges in DEL if you're in the international area... if they are open.
However beside a read receipt what are you expecting from them?