I'm test driving this install, based on your suggestions I will reinstall and configure from the beginning.

I wanted to get a liquid glass like effect on throughout my system. So I installed **darkly** and **glass**( fork of kwin blur efrect, this one had latest update so i installed this), darkly covers most of the transparency in system apps and ui elements of currently installed vlc flatpak(themeing flatpak is a headache for me). But no matter what I tried I couldn't make title bar transparent, so I installed **Klassy** and configured it(now I found an alternative method, installing and editing alpha colour scheme, but I don't know if could get those icons). 
Now everything looks great except for plasma theme. I couldn't get it completely transparent via any plasma themes(except for **maia transparent**). 
Maia transparent works great but it is outdated. On further search I found Air translucent and tried it but it is far outdated than maia. I don't know if using outdated themes causes any crashes since I get crash notification from the beginning, I couldn't tell what's causing it at all( I will research it after customizing).

My requirements are, 
1. In the first image I used Air translucent plasma theme. I liked everything except that white shade on widget menu. **I want to copy oppened app indicator** nice glass feel(if you have better suggestion I will go with it)
2. in the 2nd image as you can see, transparency works for everything except for that tooltip menu. If I could get it to working it would have been great. 

These themes updated Maia- 2021 and Air translucent -2011

3. In the third image it is flatpak jdownloader, couldn't make it transparent. Any way to make it transparent?

I only use a very few apps vlc(maybe I will switch to mpv), qbittorent, zen and brave browsers and I'm currently in search of a music player. 

[Need Help for Beginner]Trying to customize a plasma theme for transpancy