First of all, sorry about the anti globalisation and commercialism comments - I think that is largely my fault as I tend to think these things are having a negative influence on Thailand and the world - but that's just my views and not necessarily representative of Thai people. I do also recognize that these forces also have some positive points that go with them as well.
Regarding the King of Thailand. Without doubt he has been a stabilizing and positive influence on Thailand for the last 60 years. 60 years that have seen massive changes in this part of the world. But for those 60 years, Thailand, at the "top of our food chain", has had a calm, patient, caring, softly spoken, Buddhist man who clearly cares for his people. The King has never been involved with any sort of scandal. He has from early on traveled to all corners of Thailand to see and speak to his people. When the Communist insurgency occurred he continued traveling to remote areas and brought with him a medical team that would treat Thai people, no matter what their political beliefs. Now, with the violence in the South, the King and Queen continually travel and spend a lot of each year in the South.
It is the King and Queen that remind us to take care of the environment when otherwise governments, corporations and individuals may be tempted to chase greater development and profit at the cost of the environment. It is the King that reminds us to remember what is sufficient and to be happy with it. The King never kills anything. He is never angry. He holds no political power and doesn't try to pressure the country to follow any particular political agenda. He is an inventor - today's news is that Tanzania will use the King's cloud seeding technique to help ease drought there.
On so many fronts the King provides the example of what a good Thai person should strive to be. Very few of us come close and I suspect the younger generation are moving further from his example, but with him there, at least there is some reminder to some of us on how to behave. Surely this example makes it a little harder for the corrupt or greedy to get away with too much.
So what will happen when we no longer have this example and this guidance. I think mainly daily life will continue. If you have ever had a mentor or someone that set a great example to you - a parent, teacher, boss, .... and then you no longer had the influence of that person - what happened? You continued. Life will continue and some of the good things the King has set in progress will continue.
But on the other side, I feel Thailand will loose some of its uniqueness and "Thainess". I suspect we'll become a little less of a society/community - having a leader that cares for us is for sure a uniting force. Political leaders never seem to manage that, and the capitalist economy to some extent encourages people to be individuals and look after themselves. I think there will be a continuation of people getting louder and less polite and less respectful. Again having the leading member of society as a calm, quiet caring person puts those qualities as the highest things to aspire to - again politics, modern economics, TV, etc, all push another set of qualities. Even monks (or many of them) now a days often don't seem to set much of a positive example.
And so on.
Thailand will loose something great for sure. But we have been very very lucky to have the King. So without him Thailand will continue. But it will not have the example and unifying factor that it has now and if political troubles occur, it won't have someone above politics that, if need be, can quietly and calmly ask a dictator to step aside - as the King has done before. We'll have to do it for ourselves (which the Thai people have done before also).
How will it effect tourism. I think in the short term, most tourists won't notice anything different. Over 50 years - I think Thailand will have changed a lot. But that will happen anyway.