First off, always read the instructions fully, before start to make the kit. Find your questions or sticking points while you have time chase down the answet to a question. Most the time there is a phone# to get help. Use it.
That being said,, writing a good work instruction (which is what these kit recipes are) is skill that takes alot of practice to do. It can be hard to break up process into concise, outlined steps when you have only a few variables that you control directly. Try to account for multiple variables outside of the control of the person making those instructions and things get sloppy. Now press it all to a single page. No Bueno.
What i think is the bigger challenge is that the person 'writing' the instructions is taking the document for say the Caribou Slobber kit, and trying convert it to a different recipe. Taking that kind of short cut can save time if the person doing the edit is good enough to catch everything that needs tweeked, but they often do not. It many times leads directly to incorrect instructions.
In a perfect world you could input your exact equipment and process needs, and out would come a custom recipe to follow for you.
Until then, we will have to deal with sub-par instructions and lean on other resources such as books, web sites, brew clubs/partners, and yes even YouTube to fill in those gaps.
I re read the instructions and again my only fault with them is that is does not say sanitized water in 8 and 9. As to the secondary, it does add cocoa nibs into that and I know lots of home brewers that do a secondary when adding things after fermentation. I could have followed them quite easily, but then we have been brewing for years.
And for further help (on the Northern Brewer Website)
https://www.northernbrewer.com/blogs/new-to-brewing-start-here/how-to-brew-beer-homebrewing-101
How to Make Beer
They also have some instructional videos that are not bad:
How to brew beer
I would also say this is NOT a beginner kit. It has partial grain, yeast choices, additions after the fermentation and lactose (sweetness but not fermentable.
We have never used lactose but it will certainly effect the Final Gravity in a big way. Looking at some on line comments at Northern Brewer, you should expect a final around 1.026 or so. If you finish there, you would have an abv of 3.3%. The kit is labeled as medium for alcohol (at Northern Brewer).
One thing about brew kits is to upgrade the yeast as that may be the weakness of a pre packed kit. My LHBS gave me that advice. After you get a couple of complete brews done, you will become more efficient and knowledgeable.
Lot of people get small beer kits as gifts and I am sure almost none produce good beer because while quite simple, you can make errors if you do not understand the process. Get the aide, brew some more, and then re visit the instructions.
Since you had the OG (1.051), you could have calculated the desired FG. BrewSmith and other programs or calculators can do the formulas for you. The issue is that FG is a "hoped for" end. The FG is what it is. There are more than a single variable that affects the FG, so them stating it would not be necessary since a big variable is what yeast you used.
I would again highly advise getting a home brewer to help, join a club (ours has community brew days where even if you are not brewing, you can help.)
I started keeping bees about 6 years ago. I am just getting where I feel comfortable with that hobby. Lots of help, classes and books for that as well.