I wish to add effects of sound, like echo, resonances and EQ to sounds, is possible inside blender?
No and I don’t think they will ever support these effects, I have asked for many years. Blender is simply not a proper video editor. There are not enough developers available to code these features and support them.
Before doing anything like that we need VU meter first. It’s just impossible to edit anything sound related when you can’t even see if audio is at right level. I usually mixdown the audio from blender and edit levels, effects etc. On it with audacity.
Realtime waveform would be cool too. In current version vaweform stays the same if you change audio strip’s pitch and you have to listen how long it slowed down.