This is encouraging exactly what I dislike about the current ML-in-industry space, namely the fetishism surrounding being able to describe the rote steps of an algorithm and all this "X from scratch" stuff. It's good to know "this algorithm is used for binary classification" but there are so many subtleties to how the data is reckoned with through these algorithms and how that particular representation of the problem…
Not true, In my experience fitted SVMs have thousands of support vectors. The hinge loss is supposed to be less sensitive to outliers.
In general, I think SVMs are a 'terrible idea' because you can often get better fits at much faster run times with gradient boosting or you have to spend a lot of time getting the kernel just right.