Actually there are French citizens who migrated even to communist Czechoslovakia - for example well known Le Monde correspondent Fabrice Martin Plichta. BTW, are you him? He too keeps on complaining how everything in Czech R. is bad and in France how everything is good but was not able force himself to relocate back to France in 30 years :-). Anyway, I don't think that current France is attractive for Europeans. If you have any good points about why to relocate to France, feel free to share them. You know that I am quite pro-European and would like to know some good things about France when Euroskeptic mention situation in France as one of the reasons why EU is bad.
Money is only one (and not necessarily main) reasons why people go to business (or science). An important motivation is idealistic ideas to achieve something extraordinary - especially young people have these approaches.
Money doesn't bring nobility. So you're right that even families who got rich from privatizations are not a new aristocracy even though they may like opulent style. But its question whether it's wrong that virtually all citizens of the country are middle- and lower-middle classes simply because just these classes bring the economic performance. High classes and low classes have usually negative balance in what they brought to the society vs what they cost to the society.
There are a a lot of start-ups, in particular in the field of information technologies that I'm best aware of. The case of machinery / engineering is worse simply because it is not lucrative. You cannot blame young people than when they are about to decide their profession / studies, they choose either the easy way in social sciences (including economy and management) or more difficult but quite lucrative computer science. So it's up to the industrial companies to pay engineers well enough so that it would be attractive for young people to study such fields.
How does "typical Czech" looks like. I'm quite curious ;-) Of course, you can say any territory outside Prague to be "countryside" but I insist that there is no true countryside in the Czech R. because of the high density of population (you can hardly find any sparsely inhabited area) and that only negligable share of population works in agriculture is negligible 2.2%). So it substantially differs from France or the USA where you have a big capital city and then agricultural rural areas.
In bigger towns there are hardly Germans, Jews and Poles. There are mostly Slovak, Ukrainians, Russians and Vietnamese. Their share even grows due to lack of workforce for the low-paid positions but I find it wrong - if you have too many people whose heart lies in another country, then the coherence and will to care for further developing the country is fading as you can see in case of Western European countries where there is even hatred towards the host countries. Historically the genetic variations were also caused by wars and passing armies ;-) That's why I said that a territory at the crossroads of European event can hardly manage to stay homogeneous.