rm -rf

I've had my Di2 since Sept 2014, almost 10 years, and approx 40,000 miles. The shifters are still working perfectly. (I replaced the rear derailleur as "preventative maintenance" since I plan to ride it many more years.) A ballpark guess is I've done 500,000 to 800,000 shifts on the Di2.

I have large hands. The shifter hoods seem fine to me. A bit smaller than the 11 speed Campagnolo mechanical on my other bike, but I like both. I do have the Di2 hoods at a slight upward angle so the palm of my hand fits naturally on the hood+bar.

I don't notice any shift button problems, even with heavy winter gloves (or thin goretex shell mittens, that I like for the first half hour of cold starting rides.)
I've gotten used to being able to shift with a ring finger on casual rides, or doing fast, easy shifts from the drops with an index finger. I ride rolling terrain and I shift all the time, even for just a few pedal strokes before shifting again.

I have the Di2 set to "shift 3 cogs with a long press". At the base of a hill, hold both bottom buttons for 1/2 second or longer (the "long press"). That's small ring and 3 harder cogs, good. Over the top of the climb: long press both top buttons. Now it's the big ring and three easier cogs.
I don't see the need for auto shift on the front. I'll just decide for myself.

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Info:
Charge level: Solid green light: 100% to 50% charge. blinking green: 50% to 25%. solid red: "low" to 25%. blinking red: the last few percent, and usually the front stops shifting, to preserve a bit of battery for the cassette shifts. I've run out 2 or 3 times in the 9+ years, so I try to charge within a ride or two after I see the blinking green "under 50%" level. There's no advantage to letting it get really low.

Di2 crash mode: I've seen this mode when a chain got jammed. It also can be triggered by a fall onto the drive side, but I've never seen a Di2 bike fall on it so far. It acts like the Di2 is broken -- nothing happens when pressing shift buttons. It can be easily reset back to working condition using the junction box button -- google search this.

Micro adjustments: Holding the junction box button for 5 seconds, the light turns red. Now each shifter button click moves it 1/32 of a shift in that direction, for fine tuning the chain-cog position. I do this maybe once a year if I hear some slight chain rubbing noises. It's very easy to do.