I just noticed that our Dear Leader of the Mac User Group satellite meeting will be presenting in July on how to replace an old Mac with a new one. He had it easier than I did, at least his old one was still bootable, mine was too soggy for that.
We have a committee meeting on Monday, I'll offer to assist his presentation with aspects of my own experience.

Started charging the iPhone SE this morning when its battery was at 69%. Used the 61-watt charger from the MacBook Pro. For the next 20 minutes the charging was around 1% per minute with no warming up of the phone. At that stage I stopped monitoring the process.

Only if you either don’t have or don’t use the backlight.

Slim hope indeed. But I have the back of it off, battery disconnected and under a 16°C stream pf dry warmish air from a reverse-cycle A/C unit. It’s been there for about 36 hours thus far.
I noticed corrosion on the battery connector plug.

Charging test: Lightning cable connected between iPhone SE and USB-C to USB-A adaptor which is plugged into the MacBook Pro’s 61 watt charger.
No excessive heat buildup - yet.

I have three Apple laptops designed to have at least ten hours of battery life. Two of those are G3 "Pismos" which achieved the feat by being able to run for five hours on a battery & having a multi-device bay that could accept a second battery.
The other is this 2017 MacBook Pro. See pic.

battery

The base model 2011 13-in MBP benchmarks slightly higher then the top-of-the-range 2010 17-in MBP. That was the introduction of the Sandy Bridge processor and faster RAM.

Correct. Originally available in 2.0; 2.2 & 2.3 GHz, although only the 2.3 GHz shipped with 8 GB of RAM, the others had 4 GB.

I've been hearing rumours of a new iPad with USB-C instead of Lightning. One wonders what it'll be called: iPad X; iPad SE or maybe iPad SE-X?

If Geekbench benchmarks mean anything, then this 2017 2.3 GHz i5 13-in MBP scores virtually the same as the 2011 2.3 GHz i7 15-in MBP on the multi-core setting. Both computers have 8 GB of the RAM relevant to their times.