For the first one, I can see that, but my feelings will always fall to "are they ok?". That is always my idea because sometimes, people get busy. Something comes up, they have to deal with it, and they may not be in the position to contact me right away. I understand that because that's happened on my end several times. So what I like to do is just pop in every now and then and say something like:
"Just hope you're doing alright!" or "Sorry I've been so busy!"
Worrying over nothing won't make them respond faster, so I'd rather show that I'm still thinking of them AND giving them their needed space.
As for the other two -- I will have to say that they're unnecessary.
Of course, I do understand that some who do this are younger (possibly kids), but even then, I think this is unhealthy behavior. The internet will not and should not always listen to you.
Because it's so big, you're dueling with the voices of many. Everyone will not always recognize the effort you might put in when you post your work. Everyone has their reason to be online, and it's not always gonna include you. I know this every time I post here, and I am prepared for some people not to see my words or to not like it. It just happens.
And honestly, I feel it's kinda...selfish to assume you should always get attention?
It's a two-way street. If you desire attention, you have to give attention as well. You can't just ask people to promote only your work and draw only your characters and not try to do the same thing. You can't just ask people for feedback or ask for likes/comments, and not try to do the same thing.