one reason that the channel numbers don't add up could be because some channels are getting counted twice.

First my adsense stats are confusing. I now have 4 websites all attached t one G Adsense accountand the fifth to be launched by month end.
The states show Adsense Top Channels 100 impressions 2 clicks

But when I drop it it shows
Channel 1 80 impressions
Channel 2 25 impressions
Channel 3 15 impressions
Channel 4 16 impressions

But is the Top channels all the chammels rooled into one?

Also is shows clicks and earnings but a totally different figures I am now confused.

Also do I get Paid by just impressions sometimes?.

I am utterly out on a limb here.

What you may be seeing is cpm ads mixed in with the stats. Google will sometimes show a cpm ad if it decides that the income will be better from a cpm and than a cpc ad. That could explain what yoiu are seeing to some extent.

Also how many websites do you guys think it safe to have attached to one adsense account?

AFAIK there isn't a limit, but rather than make hundreds of domains, it might be better to work on a few quality ones to build up your portfolio.