What to do if I dont wanna receive DM/Messages from Discord members?
And then slide the given option, All done.
What to do if I wannna receive DM/Messages from specific members?(When I had disallowed to receive direct messages from the server members)
If you want to have specific members to send you messages you can add them as friend and then they will be able to send you DM/Messages anytime. And if then you don't want them to send you DM/Messages you can unfriend him/her.
You can change your status
Why I can't see offline members of community on Discord
On 1000 members Discord would not show offline members of the community due to bandwidth and hosting limitations on Discord’s end.
Some useful links related to Discord platform