I am being serious about the regulations, but unfortunately something like what you have suggested will take years to come into effect due to red tape and having to trial them. These huge floods that have come in the past few years havent been seen since the 1950's so noone was really prepared for them.
The other issues are the depth of the water, most of which is not very deep at all, but enough to cause the runways to close.
The large angry creatures called hippos that would not even hesitate to try and turn over a 206 or 172 on floats.
Also the passengers that are flown are not all fit and agile, in fact, a good 25% would be either overweight, old or just plain not agile enough to be able to navigate a transfer onto a boat. It is very difficult to build and maintain the wharfs big enough that will be need to reach out to the lagoons.
You idea is a very logical one, and that is something that is frowned upon this side of the world. The more illogical, the better!
The easiest solution at the moment is to build new runways on islands that will not flood and boat the passengers across to their camps.
Ragdragger, You have forgotten the high pressures, high humidities and high temps (I've flown in 49C) that are experienced here. While I haven't had a density alt as high as 11'500, I have had one at 9'300 out of Maun. An overloaded 206 out of there chewed up a lot of runway!
The runways here range from 600m to 1000m so I am presuming that your experience here is with Sefofane? All of their runways are 1000m and usually in good conditions with good approaches.
In the wet, the calcrete at a few of the runways becomes very very slick. Its not unusual to see aircraft coming into the parking bay sideways, even at very slow speeds, or watching the pilots and passengers slipping over as they try to walk around! Its almost the same as landing on ice!
I can name a large number of examples that can show that its not as easy as you are making it out to be. But at the same time, I do agree with you that it is not the extreme end of things, such as what you will find in some strips like in Papua New Guinea. I wouldn't go as far as saying bush flying lite, but a different variation in the types that you can come across. This sort of work is perfect for setting you up with contract charter operators.
You can teach a lot of things to a pilot after 50hrs. You can teach a pilot to become a instructor, a night rating, a aerobatics rating, multi rating and a IFR rating all in that time.
You can even gain a private pilots licence in that time.
50hrs of flying in the delta is very intensive and you can expect to make up to 100-120 landings. Which is more than enough to be shown the in's and out's of bush flying and the techniques that you will be more than likely to come across.
As for the instruction that you recieved in flying here, well.... that varies from company to company. I can say that mine was pretty top notch and from guys who have been in the industry for a long time, and have 5 figures in the logbook.
But back to the original comment. Yes. A van is much harder to land here than at a 2000m tar runway.
Weights, Runway contamination and conditions, Weather, Size and length of runways, Animals and Birds are all things that most pilots would never have encountered before.
Some of the guys I have met here have never landed on a nice prepared grass runway before, let alone a grass bush runway.