Can You Un-Do Noob Blogging Mistakes

I started a blog 9 months ago. It's now in the top 1,000,000 Alexa-ranked sites, but still has a Google PR of ZERO. That's because I made stupid noob mistakes.

My question is: Which of these noob mistakes can be safely UN-done. (That is, without disturbing Google indexing too much.)

1. NO KEYWORDS IN POST TITLE -- can the titles be changed?
2. NOT ENOUGH RELEVANT INBOUND LINKS -- there are some backlinks, but I didn't know what I was doing until now
3. NOT ENOUGH RELEVANT OUTBOUND LINKS -- they're too random and scattered
4. APPROVED SPAM COMMENTS -- they've all since been removed but is the damage irreversible?
5. BAD ON-PAGE SEO -- I'm working on this diligently but will it help?

Any feedback on this would be much appreciated!

Thanks in advance.

It could take some time if it was indexed by Google - but all of those problems are fix-able.

any title in any blog post can be changed. so can the content. so can inbound and outbound links. make some changes and add content pertinent to your keywords, then use pingomatic/similar things to ping your site and get some backlinks with the many easy methods mentioned in the bhw forums. blogs are always fixable.

Just make changes slowly to see what effect it has. If you totally change up your link structure of the site, or the way the url structures look, make sure you have re-directs pointing to the home page.

Slow and steady wins the race, and also keeps you from making big mistakes.

Overall, looks like you are doing all of the right things.

Thanks to all!