How do you mean unreliable? Do you mean it's down or do you mean it is not accurate?

I think I'll be using this soon: http://www.bidsketch.com/

They are on SEOMOZ's Perks http://www.seomoz.org/pro-perks

I never really do link exchanges unless they are part of a blog post. Also, I don't link to sub-par websites or unrelated websites. It's okay to link to another site and they link to you. One example is I have my BBB Membership page point to my site and I point many links from my site to that single BBB Page.

Look at the site you are going to link to and ask yourself, "Can this potentially cause a problem in the future? What's the risk?" I have turned down MANY sites wanting to link exchange, but if they are willing to write a high quality guest blog post, then I'm fine with it whether I get a back link from their site or not.

Then I wouldn't mess with a .co unless you wanted to buy up all the TLDs for you brand name. For instance, if I were HP, then I would get HP.co for trademark reasons.

If it's not a robots.txt or htaccess issue, then check GWT for malware.

If you are getting de-indexed, maybe your browser is remembering (cache) you queries. You sure you didn't write the .htacess the wrong way?

Contact Ryan Kent if you believe you need some link penalty removals.

Manually add the URLs into GWT. You can do about 500, I think.

I think this is a great perspective. In addition, I think there is great potential with G+ reviews if you can get them.

The only time I think a ccTLD is worth it is if it's for marketing to a specific country. I don't think I have ever seen a .co. I have seen many .co.uk though. What country are you in and what countries are you marketing to?

I would wait until the next crawl. Check your GWT to see when the last crawl was. Also, they may be taking their time to see if your site will disappear again. Make SURE it's up and running and no 404s.

I think you'll be okay if you have a good link profile.