While they only looked at methylation, there's also phosphorylation, acetylation, and a few others I'm not familiar with. Each of which can be inherited, and sometimes they are erased. Also changes to histones are 1/2 inherited(usually).
Also, base changes to the DNA is actually pretty common, which is the reason the sperm cells are heavily protected(not from blunt force however) and generated on a daily basis, and egg cells are even more protected in a female body. You're DNA won't be an exact match but will be pretty damn close to your own DNA. The base of the spine is also heavily protected. Your immune system also rewrites your DNA in its cells to keep the adaptive memory immune response.
What everyone else said about expression being pretty much everything, is entirely true. A gene is useless unless its expressed(And sometimes deadly if expressed).