> Yeah it's pretty annoying that group chat displays real names and profiles.

Don't use real name in profiles. You can also set Telegram to show your profile picture only to your contacts and also choose to not share it with specific users or groups in the privacy settings.

> Also group chat has a search feature for all time.

This is managed by the group administrator when setting up the group to either limit history to new members or provide all history to new members.

Did they ever say why it's not possible to have a different nick for different channels?