Body temperature is 37 degree C n it simply amaze me some user say is even hot at this temperature

Pointless to lock back as once you use htcdev to unlock your phone IMEI already captured in HTC servers. Secondly if lock back in fastboot mode you will see relock another sign you have unlock BL previously.
You can just flash stock rom through RUU if you wish
Warranty will be at HTC discretion n will be entertain if htc thinks your problem is not due to BL unlock

My last experience with HTC Times Square was sending in on behalf my friend to change motherboard of his HTC One. Took about 40+ days to get it back. Called them several times n each time standard answer waiting for spare parts n I will be informed when ready.
My last call they only said was ready for collection since 3 days ago n they didn't even bother to call me.
Consolation was a Perfect job n I cannot even see any trace of case being removed. The very minor gaps that was previously there was very improved too

Standard answer: need to wait for spare part from Taiwan.

The correct number is 1800889855.

They entertain me n had never redirect me. The number printed on TS receipt when I call auto redirected me to this number

Is my friend unit. No idea whether is SIS or Brightstar. I just sent it in to TS without even showing any purchase receipt.

Don't wait. Go n register your complaint first in order to get a replacement unit. Worse you just need to wait for it to come

Go straight to service center lah. Check website for opening closing hours. I also Google it last time. Just type HTC service center times square. I remember is open on Saturday too.

Never ever let builtin battery till empty. Is a big risk. Happen before in my nexus7 n Asus phone pad. I dismantle backcase n disconnect n reconnect back battery connectors to reboot it. You cannot do such for this phone. Try charging full n boot into ffastboot mode n reboot phone from there. If you cannot boot even into fastboot mode than I have no ideas how to solve. Try Google for solution n in worst scenario back to service center

Right. Minor gaps n if even will not be entertain. Is at HTC discretion whether is a defect to justify changing it.

I have bought 2 units from Singtel/Starhub n 2 units locally n seriously if you look closely there is very slight gap but is even. Don't be too concerned as unless it is big n very noticeable n appears uneven than I would consider it a defect. You try n go round looking for a gapless unit , best of luck. On first day of launch in Spore I have seen about 20+ demo sets at 7 outlets and all has gaps n it varies. A few units were really unacceptable to me.
If HTC did not highlight their gapless technology this would be a non issue.
My advise is enjoy your phone despite presence of such gaps. Reject it only if its appearance really annoy you n best of luck finding a very good unit.

Generally true. Apple also same policy. You will probably get brand new sets in the early days of purchase when there is no customer returns. By now the chance you get a refurbished set is higher

Yours is very bad n completely unacceptable to me.

If you have to look at it closely than it is a non issue already