I'll second what myndflyte said. Hop utilization goes down as gravity goes up, so because you had a denser (less diluted) boil, your bitterness will be a bit lower than expected. But that's the only real noticeable difference that I would expect.
P.S. I accidentally did the opposite once. My...
No, this will not kill the yeast, it will just reduce how much is left in the beer. You can still carbonate in bottles, but it may take a bit longer than usual.
Mind sharing where you got that one. The finishing hydrometer I got is 1.000 to 1.040, which is great for beer but not so much for mead and cider. My old hydrometer with over 150 points of range I often have to guess to within a point or to, this one I can get down to the half point, I just wish...
Yeah, the one I linked in particular only changes in 2 gram increments (which to be fair is 0.004% of its range, and less than 0.1oz) but it will change when I drop just a small handful of grains at a time.
If you bought that scale recently, I'd return it. The one I linked is much better for weighing grains and has been accurate for me down to +/- a few grams (not bad on a 50 kg range), and is the same prices as yours.
Your liquid units are all over the place. You mashed in liters, ran off in UK Gallons, sparged in liters, and mention a pot size in gallons (not sure if UK or US). Beersmith lists volumes in gallons but doesn't say which. I don't use Beersmith, but I'd assume it would differentiate UK gallons...
I've been quite happy with this one https://www.amazon.com/gp/product/B00KYA0RC2/
It weighs up to 110 lbs, and the display is separate from the scale, so it doesn't get hidden under the bucket or whatever you're weighting into.
At 1.005 it's pretty dry, and that recipe seems to be finishing around 1.003-1.004. Hard to tell if yours just finished a couple points higher than others, or if it's got a bit more to go. You might be safe to bottle without worrying about pasteurization, but it also might still have a few...
I'd say it's at least Kölsch adjacent... I've had commercial examples that didn't taste at all like what I expect, but the same is true for many styles.
Honestly, I think lack of Vienna is doing more to push this away from Kölsch than the yeast. I personally have a huge preference for the Früh...
Personally I go with this suggestion for the aesthetics. Unless you're planning to add a whole lot of weight to the lid for some reason, the torsion on that back panel is negligible in the grand scheme of things.
In fact, you'll hear from most woodworkers that wood glue is actually stronger...
Actually, 34/70 is a much better option for a Kolsch. It has the clean profile you're looking for, and it can even ferment pretty cleanly at low ale temps. If you can hold it around 60F (same as is usually suggested for Kolsch strains), you should be good to go.
It looks like Sound Homebrew in Seattle picked up a bunch of the 1.75 gallon PicoBrew kegs, presumably when they went out of business. I just picked up two (they have 1/$35 or 2/$60) and they were in pretty good condition.
Shipping did tack on another $27 (I'm in Sacramento, so not all that far...
Just like most beer yeasts, I don't believe EC-1118 will eat maltotriose, so you should have some remaining sweetness from the grains.
Personally, I'd go with a beer yeast that gives the right character for the beer base style you're going for.