The cache date that you see in the search results does not necessarily correspond with the last time your site was indexed.  Your site may have been re-indexed with your new content today, but the cache might still show your page from a week ago.

The best way to improve crawling and indexing is to improve your PageRank.  The higher your PageRank, the more resources Google will be willing to spend on your site.

In order to be compliant with HTML standards, all images should include alt text. This helps with users who are visually impaired. Also, it is good SEO practice.

There is no duplicate content penalty for images. Image buttons are fine unless you're really trying to optimize for speed, in which case coded buttons could be the better solution.

You can turn it off, just click on the pencil icon in the settings: http://i.imgur.com/EbxExC3.png

Hey Samantha, having text in rollovers should not  be an issue unless you are deliberately being spammy or trying to trick Google about what your page is about.

Modern web design incorporates many design elements that are hidden until the user interacts with them, such as: drop down menus, sliders, contextual help, slideshows, etc. Google understands that these are legitimate ways of presenting content to users, and not a blackhat tactic to spam keywords.

There's always the chance that hiding text could inadvertently trip Google's spam filters, but many of the most popular websites incorporate these design features, and the risk should be minimal.

I think it's still a fine way of getting links, as long as you're not overdoing it.  Instead of spamming anchor text links in the footers like a lot of companies do, you could try just having a link on the homepage, or have them write a blog post about your company with an in-context link.

Are you talking about caching or crawling?  Caching is a resource intensive process, and most sites are not cached daily, not even ones that are updated daily (try searching for your favorite news site).

From a web design & usability, a lot of people use right side navigation because it is close to the scroll bar on most browsers/computers.  So people can easily access the scroll bar and use the navigation without having to drag their cursor all the way across the screen.

As far as SEO, Google will generally filter out boilerplate content like navigation, but if you have a lot of dynamic content in there, it can impact SEO as far as where you have the navigation in the code (above the content or below the content).  However, regardless of where you place the sidebar in your code, you can have it appear wherever you want using CSS.

I don't think it's possible to add the parent category title using All-in-one SEO. You could go in and manually add the titles under Posts -> Categories, keeping the category slug the same.

That's an interesting question.  Semantic markup can be used to help Google understand what different pages are (i.e. tag pages), but it doesn't really solve the problems caused by duplicate content, namely:

1. Thin Content - Tag pages and other similar pages are thin content, with not much utility for the user, and are probably not going to rank well in Google anyway.  Even if they do rank, they won't convert as well as your main pages.
2. Keyword Cannibalization - Even if your tag pages & duplicate content rank, they could potentially outrank your main content, leading to lower conversions.
3. Panda - Too many thin content pages can lower Google's opinion of your site as a whole, leading to a Panda penalty.

Given the problems above, semantic markup doesn't really help with any of them.  Semantic markup can help Google understand what a tag page is, but that doesn't mean you want to have that page indexed.

In the categories section in Wordpress, you can add a description for each category.  This description will then show up on each category.  This is a great way to avoid duplicate/thin content by adding a bit of unique content to each category page. Also, make sure only snippets of each post appear on the category page, rather than the full post, in order to prevent duplicate content.

I wouldn't worry too much about the extra additional links, unless you're talking about hundreds of categories. Having links to your category pages is a good thing form a site architecture standpoint.