The company name and logo are an identity area which doesn't have to be too big but should be large enough to get attention when a user enters the site for the first time. The upper-left corner is usually the best position for 'left to right' direction of texts.
A tagline should be short, simple, and to the point in order to describe the website the best.
Vague or jargonistic tagline confuses users or even makes them mistrust the site - users perceive it as a marketing hype.
World-famous companies and those whose name describes precisely what they do, don't require descriptive taglines.
A business with many services can use many taglines, each for one major service on its separate website.
Users immediately want to know what the business does that is valuable for them. The tagline is a good place for describing that.
If the business is not unique, users want to know in what way does it differ from its competition. The tagline is a good place for describing that.
Important tasks expected from the user should be put above the website's fold. They shouldn't get too much competition from surrounding elements because emphasizing everything, emphasizes nothing. Identifying the most important task requires deep understanding of what users use the site for.
A website should have only one Homepage site, not many of them leading to different locations.
Use the word 'website' only when referring to the entire website. Referring to the parts of the website using that word confuses some users.
A homepage should have a different visual design that still fits the look and feel of the site. This way the users will easily identify the starting point as they explore other pages of the website.