You're getting too bogged down in things that will make no difference to your customer.

Google probably doesn't know. There are probably some incredibly convoluted methods they could use to determine it, but in general they don't know. This is why Penguin causes collateral damage and they haven't updated it again - they can't really differentiate between a spammy link / naturally placed link / negative SEO / etc.

Told to write content for a CONTACT US page! Classic content-brainwashed SEO.

The description should be long enough to convey the features of the products, the benefits of it to the customer, and any other important info. If it's 50 words, it's 50. If it's 500, it's 500. Writing to hit a number means you're going to include a lot of fluff.

Since you asked this question, it sounds like you're not a copywriter. Pay one to write your product descriptions. It will totally be worth it.

No reason other than finding all those 404 pages and doing individual URL removals for each isn't a very productive task. 404s generally have no impact on search rankings.

Don't count on Google dropping those 404ing pages from the index any time soon. We have pages that have 404d for over a year and they're still in the index.

Using your company name in the title tag isn't (generally) done with the intention of ranking for it. If you can't rank for your brand name, you've got bigger issues to deal with.

Adding the company name to a title tag is more for brand awareness. If people know your brand, it reinforces that they're in the right place. If you're not as well known, it gets that awareness going in the consumer's mind.

Because Google still has a long way to go at determining high quality content vs. low quality content, determining good backlink profiles vs. bad backlink profiles, etc. It's like people who write viruses - whatever the antivirus companies are doing, the writers are a few steps ahead. Same with Google. They're reactive, not proactive

The kind of SEO your competitor is practicing works and it always will. You don't have to follow in their footsteps, but obeying the mantra 'build great content and they will come' will take you a long time to get where they are, if it ever does get you there. Think of SEO like investing - it's all about your risk tolerance. Figure out how much you're willing to risk to get the rankings/sales/etc. that you want and go for it.

An even easier way is to check their rankings - if they're top 3 for big money terms in their niche, they're probably using some blackhat tactics. Even the whitest of whitehats are still using some blackhat tactics in the background, despite people not wanting to admit it.

http://www.seroundtable.com/google-update-brewing-18447.html

Specifically for Googlebot. I'm pretty surprised people would disagree - Stephan Spencer recommended this in a personal conversation with me.

Many people had big drops around the same time period, so likely an algorithm update that impacted you.

People who are disagreeing with this, explain your reasoning.