As a suggestion to, "You've buried the lede.": use an About link. Even his example, Basecamp; I have no idea what they do. They "help groups work together"? Details, please. Have an About link so I can go and get a complete description of what you do. This is especially important for startups. (Put it next to the Contact link.)
You forgot "microscopic font size".<p>Why is this even a thing? Who thought microscopic text was attractive? It's such a turn off. I instantly close a page if I have to strain my eyes to read the text.
<i>If you're a wedding photographer, it's probably contact you for work. If you're a website designer, same thing.</i><p>I create/sell websites for photographers and this is very true. One specific mistake I see them make is labeling their contact link something non-obvious (presumably to be hip/different). The anchor text of their contact link will be something like "inquire" or "connect" or "say hi". I should probably run some tests but my hunch is this is bad.
I rather like the Parallax portfolio sites. They simply value emotional design over usability to offer an immersive experience. It's a different approach, and for a portfolio site, I'd argue it's better.
I completely agree with your first point, 'You've buried the lede' and this is a mistake I see on a daily basis. Great design should never say "look at me" it should always say "look at this".<p>The first steps to achieving this and therefore avoiding the mistakes you mention are to cohesively join your UX and UI teams or designers into one fluid process. One will never work well, without the other. What are you saying and how are you saying it is the basis for ensuring your core company message is translated effectively over any medium.<p>If in doubt always ask yourself, 'would my mum get it', she might not be the target audience but your design should be that simple to understand and decipher. No-one wants to have to go to an about us page, or scroll endlessly down a page to 'get it', otherwise why do we bother having headlines on newspaper articles? Simplicity is difficult, but this is the challenge all great designers should embrace.