Water damage repaired & off-axis capacitor

Hi everyone, I tried to be as much precise I could, hope I succeeded.

The iPhone 6s we are speaking about had a water damage near the sim tray (white dot near the sim tray turned red, while the white dot on the upper side of the motherboard, “near” the camera is still white), it then was repaired (not by me, so I do not know anything about the fixing process) and worked for about one month until one night I turned it off, put it in charge, and never powered on again.

- Specification needed: I’m not a pro repair tech, but I’m not even a beginner at all, I made many iPhone repairs, sometimes even involving soldering, so feel free to suggest whatever you think is appropriate.

I opened it for the first time and here came the first question:

1) shielding over A9 chip and baseband is unsoldered and easily removable, is It a critical problem?

Then I continued looking at the motherboard and I found a small capacitor in the baseband area off-axis, I then slightly tried to move it with a needle and it moves!

2) I uploaded a picture of the off-axis capacitor at issue, it is a critical problem, right?

Additional consideration before final question:

- when I put the charger on, I have the feeling the battery is not charging at all, the charger does not get hot even a bit, as well as the battery, BUT (maybe it his important) there is electricity flow along the phone, because passing my finger over the battery I feel that sort of vibration common when something disperses energy.

- I inspected the whole motherboard a lot but I couldn’t find any oxidized part except for a small mark near the sim tray.

What should I do in your opinion? I tried to put in charge the iPhone keeping firmly the capacitor in his position but anything happened, is this an adequate attempt? Should I replace it? If yes what capacitor it is? Or should I try soldering it?

Thanks a lot for the help.

Post Scriptum Question: there are some black dot near A9 chip, it is normal (thermal paste) right ?