Q1). Which is a better course between mastery in digital marketing (including various social media platforms, Google Analytics, AdWords, etc.) or mastery in Google AdWords?
Ans1). Before answering this question, I will like to explain something.
If you are doing the above to help you get a job, there is not a single course which anyone in the industry acknowledges. The only thing that matters is the knowledge you have and what you can do, especially the strategies you can create to deliver on Digital platforms.
I take interviews on a daily basis and have never seen once where the person has done the course from.
If you are doing it for increasing your learning, then above all platforms are awesome however do not pay for any certifications. Learn that tool by using it to its full extent.
The more you use a tool, the better it is for you.
Google Ads + Google Analytics are an awesome mix (it is also in demand)
Become an expert in one and you can continue learning others.
I hope this helps, do visit my website for more such relevant tips.
Q2). What are some of the unwritten rules of internet marketing?
Ans2). Not sure what are you looking for by the unwritten rules of Internet Marketing as there were never any rules to start from.
yes, there are Laws for each country however there are no as such rules that exist.
If you are looking for hacks that can help you achieve good results in Internet marketing then you have to specify what platform or medium of marketing you want to know that hacks about.
Wishing you luck in finding the unwritten rules.
Q3). Will building links (backlinks) from Wikipedia ban my website?
Ans3). What is that you will achieve from getting a backlink from Wikipedia or any other platform.
Please try an understand something.
This is 2019 and Google Ai (Rank Brain) is super smart, it is able to understand what links were made manually and what links were made naturally (Organically). You will never get any benefit of these backlinks.
Few additional points almost every high DA website either does not give a backlink or if they give one it is a No Follow.
You should not focus on creating backlinks, the purpose should be to generate traffic from those backlinks. If you get enough visitors from that backlink than the page will start ranking because of the high CTR(click through rate).
Read more about what SEO OFF Page activities to do and avoid. I have also created a list of website where SEO guys usually put backlinks.