Everyone is mining at dedicated,
what happens if it forks, what is a fork, how do they occur & how can they be avoided? (besides balanced mining spread over many pools & solo miners)
A fork is when the block chain is branched off into separate blockchains. This doesn't happen automatically but anyone that has over 51% of the net hashrate can do this if they so choose. It would essentially split coino into coino 1 and coino 2. If this happens, everyone has to update their wallets to get back on the same block chain and anyone that was mining coins on the other block chain between the time of the branch and everyone updating their wallets will lose everything they mined during that time period.
Even without forking there are other things that holding over 51% of the hashrate could allow such as preventing solo miners or miners from other pools from ever finding valid blocks, reversing transactions, double-spending etc..
Again, this has to be done with malicious intent but it is better for a crypto coin to not ever be in a position where any 1 person can take it down. The owner of dedicatedpool has temporarily closed registrations in order to get the hashrate more evenly spread out which I feel shows that he has every intention on doing what is best for the coin and not taking any ill-advantage of his control of the network.
I wouldn't worry about anything bad happening right now but people just need to try and spread out which will keep confidence in the coin high and guarantee that the currency can't possibly be harmed by anyone.
I haven't done the math so I don't have exact numbers but there reaches a certain point where it doesn't even make sense anymore to mine at the pool with the most miners. There are a finite amount of blocks (1 every 25 seconds). Even if the top pool held 100% of the hashrate, they wont possibly find anymore than 1 block every 25 seconds. But you sure will split those blocks up between a ton of people. At a mid-sized pool you will likely find blocks slower, but you will take a larger share of each block.
Theoretically, you should earn the same at both pools, as long as the smaller pool is actually finding blocks at a regular pace. So if you are making the same amount of coins by huddling together in one pool, or spreading out among multiple pools, why not spread out and provide security and stability to the network? There is no point in having all of these coins unless everyone does what is best for the value of the coin. In the case of net hashrate, that means spreading out.