confirmation time limit Reading How does mining works and towards the end of the explanation,


  As more people start to mine, the difficulty of finding valid blocks is automatically increased by the network to ensure that the average time to find a block remains equal to 10 minutes. 


But in Why do I have to wait for confirmation? 


  Each confirmation takes between a few seconds and 90 minutes, with 10 minutes being the average.


Since "finding a block" is "confirmation" of a transaction, the above quotes seam like a contradiction.

The other question is why the difficulty increases when more mining power is available? one would thing the opposite should be true. I must be missing something. Any  explanation for this? Thanks
The difficulty of the network adjusts in proportion to the hash rate, so that on average a block is found every 10 minutes. Of course, it's still a random process, so sometimes blocks are much shorter and sometimes they're much further apart.

As a result, if more hash power gets added to the network, the difficulty has to go up to compensate. Otherwise doubling the hashrate would result in one block per 5 minutes instead of per 10 minutes.

I don't understand where you think there is a contradiction, but feel free to clarify.