Hi,
First of all, thanks a lot to all of you for the detailed responses. Amazon didn't explicitly state that this is refurbished, so I'm assuming it is a brand new set. However, from December, when the phone first went on sale here in India, people were complaining of signs of the phone having been previously being used like the name of the device being "Jane" and not "V30+" as is default. I had no such signs or any wear and tear on the front or back. So I can reasonably assume that this is new.
The blue tint was noticeable before I changed modes, which is why I had to change it. And yes, even a slight tilt causes part of the screen to change colour. But as you say, this is a common phenomenon in OLED displays, and yes, I know it's pronounced in mine, but while watching videos or pics, it isn't noticeable that much. Maybe I would grow accustomed to it and learn to live with it, since going through the replacement procedure with Amazon is a pain in itself as I have experience of it!!
I still haven't inserted a SIM in it and started using it as my daily driver, as I first want to layer it with protection front and back, and only then would I take it outside the house!! So signal strength is not the issue. I am just connecting it to the home wifi and using it to just watch videos or browse the net. So the dip in battery is all due to the processes going on inside it.
The intermittent waking up is not regular. For some charging sessions, it does not do that, while at other times, it's doing that. I would have to charge it some more times to get a pattern. I see your point, though, as I had set it on charge while the setup was going on and the waking could have been just due to an installation being completed. I would have to ask though: does this phone have such a feature where it would chirp and wake up constantly until you viewed a new notification?
Lastly, let me take your advice and use it for some more days before judging on its battery life since with this sporadic use, (i.e. I just use it for some time before leaving for work and then after coming back from work), the battery is still at 65% after 2 days (it arrived the day before yesterday when I charged it to 100%), and seems pretty solid.