Adgroup disabled

[Jon12345]

I had a single term on broad match in an Adgroup. It was disabled after 2 days. About 2,500 impressions and a 0.4% clickthrough.

What is the criteria to keep your Adgroup or keyword alive?

After how many impressions is it then calculated before being disabled?

If you have an Adgroup with lots of keywords, will it show disabled next to the disabled keywords or will they just disappear after a while from your keyword list?

To re-open the Adgroup, do I need to delete the Adgroup or just delete the keyword and re-add the keyword?

Jon

[Jon12345]

Oh, and while I am at it, I have a keyword at risk that has the following stats:

Status: At Risk
Clicks: 826
Impressions: 10,869
CTR: 7.5%
Avg. Pos: 1.1

Why on earth would that be at risk?