Cache Pages drop

Hi guys

Need some tips from pros here.

My site has a high Pagerank, big G simply loved me since the day we started back in 2000 until early this year when suddenly a huge chunk of my cached pages were dropped by more than 50%. We lost majority of our traffic and our ads3nse went down by 70%. It really knocked us out.

We don't spam since we started, but I really have no idea why G did this.

I then realised we weren't the only ones affected by the change in G's algther major sites are also affected and I suspect, interlinking within our domain is the main problem, but i could be wrong.

Although the earnings are rising slowly now, we are nowhere near where we used to be.

So my question
1) Is number of cache pages important? Low cache pages = low traffic?
If it is, what is the best way to get google to reindex them?

2) I dont have any real SEO plan, except to build backlinks to my main site via commenting. Any plan recommended (blackhat) from the pros here?

3) Any good SEO tool you would recommend?SEnuke, Xrumer?

4) Are Link Pyramid, Linkwheel any good?

Help this brotha out, guys..any inputs is much appreciated and sorry for the long story

Did I post this in the right place??

If your site has been effectively whitehat since 2000 I would hold off a bit before trying anything that could get you blacklisted for sure. Google changes their algorithms very often, so this could just be a transient phenomenon, especially if it's knocking down legit sites. If it doesn't improve in a month, I would then consider those things you mentioned--for now I would just ride it out while maybe doing some research into possible new competition.