I have no idea what Im doing | Watermark and cloud

Case A

I have 5 videos on my iPhone - I wanna turn off the sound from videos and put watermark (text with low opacity) to all of them quick. 

Case B 

I have 4 videos on Laptop with windows 10, I wanna turn off the sound from videos 

and put watermark (text with low opacity) to all of them quick and have this videos on the phone quickly too. 


What I was doing now: 

Case A:

I opened premiere rush on mobile and added video to cc and then opened it in premiere on laptop - quick edit and save it - but from the beginning on computer video was much brighter so...

I just send it to google photos and download on laptop and then edit only with media encoder - turn off audio and put text watermark. What is not really working when I change opacity for text watermark - the background of the text changing color from neutral to black and I wanted to only apply less opacity to font - dont want any background on the font. I just leave it like this and this is much faster but Im sure its not the optimal way Im doing that with the google photos instead of using adobe cloud - I dont know how to properly use it and apply good opacity for font watermark. Is media encoder my fastest and best option? 

Case B:

doing same stuff in media encoder but I dont know how to have this video on mobile using adobe cloud after.