Are there any ways to increase the Bitcoin maximum coin limit, as a wider adoption would mean there would be a lot of real money chasing fewer number of coins? Also can one hold a fraction of a coin?
A single Bitcoin is currently divisible up to 8 decimal places (giving you 21*10^14 units of money, or about 2.1 quadrillion units), nothing stops it from being divided further with small protocol change. In order to change the limit of Bitcoins created, one needs to change the protocol and force most of the Bitcoin network to adopt the change, which can be quite hard to do. This hard limit of the amount of Bitcoins is one of the features of the system, not a flaw - it is meant to fight against inflation. If for some reason you want a cryptocurrency without a limit (hint from Lohoris: you don't), try browsing for alternatives.
All in all, there will be enough Bitcoins to go around for everyone for a long while.
The reason there is a cap to the amount of Bitcoins is to create a design that should increase in value longterm as opposed to decrease forever as FIAT does. Noone would want to invest in a new currency that was designed to decrease in value.
Since there is no limit on how small size a Bitcoin can be divided to. A single coin could be made enough to cover the whole earth if all the 21 million coins are lost.
Well, there's coding.
Of course like many pointed out things, it might not be necessary. Every Bitcoin is divided in one hundred million units if I'm right. That should keep everything all right for now.
The thing is that a change like this (eliminating the limit) can cause problems with how the currency will be regarded (it can make it worthless). The alternative is to make more subdivisions...like splitting a Satoshi into 1000 units to keep miners mining but the thing is that miners have "tricked" the system already and they will continue to do so.
Well then, what needs to be happening is similar digital currencies appearing periodically along the way because future generations should also have the ability to mine newly formed currencies so that they can enjoy the freedoms we can now. Silver runs alongside gold, never as valuable, but surely as effective a resource to be traded for goods and services. Likewise other digital currencies, should be freely capable of running alongside bitcoins for future generations to enjoy the value of.
Perhaps though, due to the lack of intrinsic value of any digital currency, which is essentially as great as the next massive EMP blast, the new digital currency should perhaps wait until bitcoins have grown substantially in value before lending itself as another easier currency to mine. And there should always be exchange rates between the individual digital currencies. However, we must be careful to avoid what was caused by having the gold and silver standards of our nation's past, provided popularity of digital currencies allows for such a problem as what happened back then.
However, I think that this is a great model. It's literally modeled after gold and oil, both of which are finite resources that have substantial value. One has been used as actual money and a measure of past national economies while the other has been used as a commodity more so than money simply because it is not readily available and traded for goods and services.
Everyone, please remember, bitcoins are digital, their intrinsic value is less than nothing because they essentially are absolutely nothing. This means that in order for them to be worth anything, very similar to our Federal Reserve Notes that we color green in this nation, someone has to be willing to trade viable currency for them or to take them in trade for goods and services. They're not like gold or silver, which are physical materials that anywhere in the world would generally take in trade for goods and services at a time when there was lacking an official currency.