Using Brewtoad, which recently was changed for the worst in that it won't give the tenth of a percentage for ABV now, shows that, if brewed according to the recipe, gives about 3.5% ABV, 12* L (same as SRM?), and 32 IBU's if done at 60 mins and 5 mins for the hop schedule. Using LME instead appears to change the ABV to about 3.2% I'd guess. Not a big deal. Since the extract was boiled the whole time the color is likely to be a little darker, by how much I'm not sure, and this was based on ultra light LME BTW.
One pound of DME provides approximately 46 gravity points, that is, a one gallon solution containing one pound of DME has a specific gravity of 1.046.
1.75 x 0.046 / 2.5 + 1.0 ~= 1.032
With a seventy-five percent apparent attenuation rate, we should end up with a final gravity of 1.008.
Alcohol by weight (ABW) = (1.032 - 1.008) x 105 = 2.52%
Alcohol by volume (ABV) = 2.52 x 1.25 = 3.14%
However, there is no way to know what the apparent attenuation of the fermentation was if original and final gravity readings were not taken.
The final hops should have been added out knockout, which is the proper brewing term for "time 0" ("flameout" is a slang term that entered the amateur brewing lexicon in the last decade or so mainly via web forum usage). The average Goldings hop harvest yields a hop cone that contains around 5% alpha acid. We are only using three quarters of an ounce for bittering (the knockout addition does not add bitterness). With a 1.032 boil gravity, we have a 60 minute hop utilization rate of 0.276.
IBU = (5.0 x 0.75) x 0.276 x 75 / 2.5 = 31
The above calculation assumes a non-concentrated boil. The actual IBU level will be lower if the boil volume is less than two and half gallons because the boil gravity will be higher. The IBU level is also going to be lower if the actual hop used had an alpha acid (AA) rating lower than 5 (the whole Goldings that I currently have on hand have an AA rating of 4.7%).
The major snafu was using LME instead of DME. LME only provides 36 gravity points per pound; hence, the extract mass needed to be adjusted to 46 / 36 x 1.75 ~= 2.24 pounds (i.e., a pound of DME contains 1.28 times more malt sugar than a pound of LME). Using 1.75lbs of LME in place of 1.75 pounds of DME, results in an original gravity of 1.75 x 0.036 / 2.5 + 1.0 = 1.025.
I have never heard of a five-quart pot, but they may exist. The most common large pot in the average household kitchen is six quarts. Considering that it is almost impossible to boil six quarts in a six-quart pot, let's assume that Skitter managed to boil 1.25 gallons. That boil volume doubles the boil gravity to 1.050, which yields a sixty minute hop utilization rate of 0.231.
IBU = IBU = (5.0 x 0.75) x 0.231 x 75 / 2.5 = 26 IBUs
With that said, 26 IBUs of kettle hop bitterness in a 1.025 O.G. beer is going to result in sharp back of the mouth bitterness because there is so little malt to offset the bitterness. The good news is that the bitterness will mellow if Skitter gives it enough time. The beer will also taste less bitter if it is allowed to warm up to cellar temperature.
In the end, experience is the best teacher. More is learned by making mistakes than doing everything right.