Normally, I would say don't do it because wasting character space in the title area is a pet peeve of mine but maybe it helps you with click through--maybe not.  At number 10, it doesn't seem to be hurting your rankings but maybe it is-- have you tried it without the exclamation point to see if your result moves up?

While those footer links back to the agency that created the website used to be commonplace and sought after, it's shaky ground today--even just one or two no-followed links from a client's  site could get you in trouble--in the future.

Today, a followed link or two from the footer of a client's home page and another one from some an interior page (each link having different, non-exact match anchor text) may still provide your site some advantage--and that's the problem.  Using those links to your advantage may help your authority in the present but you shouldn't be surprised if that authority is stripped at some point in the future.  You know what it looks like when authority is stripped?   A penalty.

If you are still getting a followed footer link or two from each of your clients, that shouldn't be your only means of building authority--it should be a supplemental means.  You really need to work just as hard as any other site in any other industry to build editorial links back to your site in order that you not suffer an authority adjustment down the road.

The best practice is to nofollow those links in order to prevent them from giving you problems in the future.

As Matt said, boilerplate stuff is a tossup but your about page should be rankable for some unique facet of your business and for that reason, I'd be sure to 301 (if the pages are different) or canonicalize (if the page content is the same) to your preferred version.

No, as long as you're not also spamming your page copy with your specific target keywords.  Nonetheless, it doesn't look very professional.

More relevance while leaning towards click through rate/call to action.  It's a balance.

suchde, as says premiooscar, it is not a given that Google uses your meta description in the snippet.  In fact, in Google's own words, "Google will sometimes use the meta description of a page in search results snippets, if we think it gives users a more accurate description than would be possible purely from the on-page content." In fact, you can  find that for each different search query that your page comes as a result, you can have a different snippet--it could be the fully from the meta description, fully from the page copy, or a combination of page copy and  meta description info.

• https://support.google.com/webmasters/answer/35624?hl=en
• http://moz.com/blog/why-wont-google-use-my-meta-description